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Fatima Ahmed: Hi Yeasin, please send your answer for the Loudspeaker quiz in an email. Check the instructions on the quiz page. I deleted your answer from the comment section for that reason. Let me know if you have any other questions. Thanks.
Adam Petropoulos recently got admitted to the culinary institute named Le Monde in Athens, Greece. His career goal was to become a chef. He loved food! He wanted to learn the art of flavor...
Mesbah AbirTo understand this, at first we have to know about pressure. In the light of physics, pressure is the amount of force applied per unit area. That is P=F/A. Now in case of cutting something using a knife, you have to put pressure on the thing you want to... moreTo understand this, at first we have to know about pressure. In the light of physics, pressure is the amount of force applied per unit area. That is P=F/A. Now in case of cutting something using a knife, you have to put pressure on the thing you want to cut. It is mentionable that,less the area is, more the pressure will be. That means pressure is inversely proportional to area. You know that, a sharp knife have less area on the cutting edge than the blunt one. As a result, by giving equal force the pressure by the sharp knife will be more than the blunt one. To do the same work, you have to give more pressure on the blunt knife for which the possibility of slipping the blunt knife with greater force will be more. And that would be dangerous for you as this can cause serious damage. For this reason, it is recommended to use sharp knives rather than blunt knives to cut vegetables. less
June 21, 2021
Tawhid MimA dull or blunt knife is a lazy tool. It doesn’t want to work so it makes you work harder. That means using more pressure or a harder chopping motion.
If you’re using a knife to peel a potato or carrot, the dull knife can stop on an irregular... moreA dull or blunt knife is a lazy tool. It doesn’t want to work so it makes you work harder. That means using more pressure or a harder chopping motion.
If you’re using a knife to peel a potato or carrot, the dull knife can stop on an irregular surface, forcing you to use excessive pressure to get past it. If the knife blade suddenly slips, you’re likely to cut yourself as it suddenly speeds up.
Dull blades make cutting meats harder and make you use extra force to cut through any tougher part of the meat. Once it cuts through and can move easily, quite often you’ll cut your other hand when the blade moves quickly due to the force you’re using.
A sharp blade cuts easily through most foods and only light to moderate pressure is required. It’s easier to guide and control a sharp blade due to its consistent cutting ability. less
Khokon RoyThe main reason it's safer is that a sharp knife will do what you intend to do - it will cut things - it will cut cleanly and decisively - so as long as you're not doing anything stupid (like cutting toward your fingers), the knife will perform the... moreThe main reason it's safer is that a sharp knife will do what you intend to do - it will cut things - it will cut cleanly and decisively - so as long as you're not doing anything stupid (like cutting toward your fingers), the knife will perform the cutting operation with precision and predictability, and with minimal application of force.
A blunt knife, on the other hand, is quite likely to slip off the surface of some harder or tougher objects - and this means it will go in a direction you did not intend - perhaps in the direction of your fingers. To compensate for the loss of cutting action, you'll find yourself applying more force - which means you may no longer be in control of the blade; you might not even be holding it properly any more - and then, when the blade still slips and goes where it isn't meant to, it will arrive with far greater force, possibly cutting you quite badly.
A blunt knife also tends to crush the food, rather than cutting it - so with something like an onion, the layers will... less
June 21, 2021
Imad MustafizThe main question that arises is that a sharper knife has more penetrating power and can easily cut through someone's skin in case of a slip causing an incised wound. But a blunt knife will create laceration which will create irregular edges in the wound... moreThe main question that arises is that a sharper knife has more penetrating power and can easily cut through someone's skin in case of a slip causing an incised wound. But a blunt knife will create laceration which will create irregular edges in the wound creating a risk of infection. According to physics, we know that a unit of force (1 newton) applied to a unit area (1 meter squared) perpendicularly will create 1-pascal pressure. The formula being P=F/A (n/m^2). So, the more we apply pressure to the handle of the knife, the more the pressure is in a smaller surface area. This makes the point of contact of the vegetables precise and allows swift and clean cutting. Whereas the blunt knife having a larger surface area, won't have the same penetrating force which will result in a twisting force called torque. So the knife will rotate and cause injuries to the hand. less
June 21, 2021
Taarik HasanIn equation form Pressure = Force/Area. Here the Pressure is determined by equal Proportionate of Applied force, and Area is disproportionate. If the area of applied force is less/thin/small, the pressure will increase on same applied force.
If the... moreIn equation form Pressure = Force/Area. Here the Pressure is determined by equal Proportionate of Applied force, and Area is disproportionate. If the area of applied force is less/thin/small, the pressure will increase on same applied force.
If the Force is fixed, then the Pressure will increase by thinner (Sharp) Area of contact. The knife is the Area of contact with carrot.
The Area is constant then increasing the pressure must go through putting more Force on the knife. (The Knife is dull then the area of contact is fixed with a thick characteristic.)
(..) less
June 21, 2021
Taarik Hasan(..)
Thinner/sharper area puts more pressure on surface that helps to use less energy as pressure for a person to cut the carrots smoothly. Dull knives
need to use more force and it is kind of slippery cause it doesn’t cut smoothly.
Possibility of... more(..)
Thinner/sharper area puts more pressure on surface that helps to use less energy as pressure for a person to cut the carrots smoothly. Dull knives
need to use more force and it is kind of slippery cause it doesn’t cut smoothly.
Possibility of slipping the path during cutting is dangerous.
It can go to the finger just placed millimeters after the
cut area of vegetable. Also more pressure on carrot may not cut effectively but for human body pressure with a dull knife is more dangerous than a sharp knife. less
June 21, 2021
Nanjiba NaowarImagine two knives, Sharp and Blunt. Sharp must have a thin edge and the Blunt has a thick edge. So the edge area of blunt is bigger than sharp. When you put the same force on both of them, the force is distributed in the smaller portion of Sharp's edge... moreImagine two knives, Sharp and Blunt. Sharp must have a thin edge and the Blunt has a thick edge. So the edge area of blunt is bigger than sharp. When you put the same force on both of them, the force is distributed in the smaller portion of Sharp's edge area and makes more pressure directly on surfaces and makes a quick cut. The same force will be distributed in the bigger portion of the Blunt's edge area and as the force spreads in a bigger place, the pressure becomes weaker on the surface and makes it harder to cut thoroughly. Sharp knife bite the surface with its thin edge and the blunt knife can't sit properly, so it becomes slippery and risky.
In physics term, force/area=pressure. Here, forces are equal. Sharp knife has a smaller and blunt knife has a bigger area. When you divide the same number with a small and a large number, they result in a big and a small number(pressure) respectively. So the pressure of a sharp knife will be greater than blunt one. less
June 21, 2021
Sourav ChowhanSo the phenomenon is related to the Pressure of physics.
We know pressure very well right? Pressure is a physics phenomenon like if you Push some object, you're are actually employing pressure theory. To cut something you need to give some push/Force to... moreSo the phenomenon is related to the Pressure of physics.
We know pressure very well right? Pressure is a physics phenomenon like if you Push some object, you're are actually employing pressure theory. To cut something you need to give some push/Force to cut or chop that object right?
The equation of pressure is P=F/A, Here "P"(pressure) refers to pressure, "F"(Force) is referring to Force that you're applying to that object and "A"(Area) is where you're applying the force. Ever seen any car glass-breaking video on youtube or on any social media. They use very sharp head hammers and the glass breaks. But when they use an ordinary hammer the elasticity of the glass reflects the hammer. Now we're back on that equation P=F/A, From this equation you can see the "P" is inversely propositional to "A" and "P" is proportional to "F", if you don't know what is inversely propositional and proportional then it's for you. "Inversely... less
June 21, 2021
Sourav Chowhanpropositional in that equation means if the value of the area is too low then the pressure will be too high and propositional means if the value of "F" is high then "P" will be high too.
Brunoise cut is a special type of cutting food... morepropositional in that equation means if the value of the area is too low then the pressure will be too high and propositional means if the value of "F" is high then "P" will be high too.
Brunoise cut is a special type of cutting food into smaller dice in even 3mm cubes.
Adam was trying to cut the foods with a blunt knife, so the area of the knife-edge was massive and that's why he needed to give more pressure and the chopped won't be nice because he wanted to chop the vegetable in small dices. But it won't be possible with Dull or a Flat knife. less
June 21, 2021
Sourav ChowhanHe used the blunt knife and the result is he almost cut his fingers because he needs to give more force to cut, remember that equation of pressure??? to cut with a blunt knife he needs to give more Force. But if he had used the sharp knife where the edge... moreHe used the blunt knife and the result is he almost cut his fingers because he needs to give more force to cut, remember that equation of pressure??? to cut with a blunt knife he needs to give more Force. But if he had used the sharp knife where the edge so sharp and it can go through anything. The area of a sharp knife is so small, and from that equation, you have guessed that the pressure will be high. So it will be so easy to cut vegetables into dices or any shape he wanted, That's why chefs sharpen their knife before use. But during the cut, he needs to careful that it doesn't hurt him. less
June 21, 2021
Sourav Chowhan
With a sharp knife, he doesn't have to give much pressure on cutting, so that's why it will be safer.
That's why it is safe to use a sharp knife than a dull knife. It will save you both time and energy.
So next time you cut a tomato please use a sharp knife.
June 21, 2021
Afnan AlamFrom Pascal's Law, we derive the equation of pressure as follows-
P=F/A
where, P= applied pressure on the object
F= force applied on the... moreFrom Pascal's Law, we derive the equation of pressure as follows-
P=F/A
where, P= applied pressure on the object
F= force applied on the object
A= the area of the object where pressure is applied
Let's consider in above circumstances, adam applied the same amount of force on the carrot he was cutting with both the sharp and blunt knife. His ease of cutting will be dependent on whether the area of applied force is lesser than the other or not. Now, with common sense, we can easily understand that the sharp one has a lesser area of pressure than the blunt one because the edge is much narrower. So, more pressure will be put on using the sharper one.
The risk of using a blunt knife is that it may slip the vegetable adam is cutting and may severely injure his hand. We don't want any harm to be done to this nice fellow. That's why his instructor advised him to use a shape knife in order to cut them with ease and safety while taking less time. less
June 21, 2021
Abrar Ibne Amin JimThe incident refers to pascal's law: P= F/A. Here P= Pressure, F= Force and A= Surface Area(The surface area of the object on which force has been applied). The P and A are inversely proportional to each other.
Adam tried to cut the carrots using a... moreThe incident refers to pascal's law: P= F/A. Here P= Pressure, F= Force and A= Surface Area(The surface area of the object on which force has been applied). The P and A are inversely proportional to each other.
Adam tried to cut the carrots using a blunt knife. He couldn't do that in brunoise cut and he almost cut his hand. His teacher mentioned that the sharp knife is efficient to cut any food. If you try to cut a cucumber using a blunt knife it would require you to exert more strength/force. The knife may slip if the sharp end is too thick. Whereas if you use a sharp knife you can efficiently do that by exerting less strength/force
This is because of the force and the surface area. The surface area of the sharp end of a blunt knife is more than that of a sharp knife. We get from pascals law that Pressure is inversely proportional to the surface area. So if you apply the same amount of force for both the knife, the sharp knife would be more efficient. So sharper knife is safer in cutting food... less
June 21, 2021
Yeasin ArafathIn this case, Adam is trying to cut the Carrot. So he has to apply force in the knife which makes the pressure cut the Carrots. Here another physics term arises that is cutting Area of the knife. With all of these things, we can get a relation from... moreIn this case, Adam is trying to cut the Carrot. So he has to apply force in the knife which makes the pressure cut the Carrots. Here another physics term arises that is cutting Area of the knife. With all of these things, we can get a relation from physics that is Force=Pressure/Area
Here we can see that Force is inversely proportional to Area . This means that if Area is increasing then Force will decreasing & similarly if the Area is decreasing then the Force will increasing with the proportion to each other.
To cut the Carrots properly Adam had to give more pressure when he used the dull knife. Because the dull knife’s cutting area is more than the sharp knife. Moreover while giving more pressure for dull knife it might be slipped and cut his hand. As cutting Area of the sharp knife is less. So he had to give less pressure & did his work nicely and more safely. less
June 22, 2021
Tanveer Tausif RatulThe above phenomena is related to “PRESSURE”.What is pressure?Pressure is defined as-“FORCE PER UNIT AREA”.Let,we apply a certain amount of force ‘F’ by a knife which has an area ‘A’,by which it will apply the load on another object,a... moreThe above phenomena is related to “PRESSURE”.What is pressure?Pressure is defined as-“FORCE PER UNIT AREA”.Let,we apply a certain amount of force ‘F’ by a knife which has an area ‘A’,by which it will apply the load on another object,a pressure will be created there which
can be denoted by ‘P’.If we put these in an equation using PASCAL’s law,it will be-“P=F/A”.From the equation it can be said that,if the applied force is constant on a plane,then pressure is inversely proportional to area of the object by which load is being applied.So,area increases,pressure will decrease & area decreases,pressure will increase.
Now consider,Adam is giving 10Newton’N’ force both on sharp knife and blunt knife while cutting the vegetables.When the knife is sharp,the area of the edge of knife is small but for blunt knife,area of that edge is larger than sharp knife. As a result,when adam is giving that
force by sharp knife,the pressure exerted by the knife on the vegetables will be... less
Tanveer Tausif Ratullarger.Because of that,the vegetables can be cut very easily & safely.But while using blunt knife which has large edge area,amount of pressure will decrease for the same 10N force.As a result,he will have 2 options.One is,reducing the edge area of... morelarger.Because of that,the vegetables can be cut very easily & safely.But while using blunt knife which has large edge area,amount of pressure will decrease for the same 10N force.As a result,he will have 2 options.One is,reducing the edge area of knife or increasing the applied force.The 1st option is impossible,so he must increase his force on that knife to cut the vegetables.But a blunt knife often slips,so it can easily injure his hand/fingers.Therefore,it is safe to cut vegetables with sharp edged knife. less
June 23, 2021
Md Mahedi HasanA dull knife is actually more dangerous to use than one a sharp knife. Cause a dull knife requires more pressure to cut. It’s increasing the chance of the knife can slip with great force behind it. Sharp knife bites surface much
readily.
For example,... moreA dull knife is actually more dangerous to use than one a sharp knife. Cause a dull knife requires more pressure to cut. It’s increasing the chance of the knife can slip with great force behind it. Sharp knife bites surface much
readily.
For example, if you’re cutting a carrot and the blade is
really dull. It will need more pressure to get through the carrot. Once it’s through the carrot, there’s a greater chance for the pressure to lead to slippage or a lack of control.
Sharper knife utilizes edge geometry to make a cut. While a dull knife uses force. A sharp knife can glide through materials without much effort. on the other hand, a dull knife is clumsier & less user-friendly. less
June 23, 2021
Khadeeza Afruz ShammeePascal's principle of pressure describes this knife phenomenon. As a scalar physical quantity ,pressure is defined as the force per unit area applied perpendicular to the surface which it is applied .
The elementary mathematical expression for pressure... morePascal's principle of pressure describes this knife phenomenon. As a scalar physical quantity ,pressure is defined as the force per unit area applied perpendicular to the surface which it is applied .
The elementary mathematical expression for pressure is giving by ,
P = F/A
Here, P is the pressure , F is the force acting perpendicular to the surface to which this force is applied and A is the area of the surface .
The same force applied by a sharp knife with a smaller area of contact will exerts a much greater pressure than a blunt knife having a considerable larger area of contact .
Once a blunt knife is through the object (vegetable or other food), there is a greater chance for the pressure to lead to slippage, skidding and injury. A sharp knife can cut using the edge of the e knife with a safer slicing. Rather, cuts from sharper knives can actually heal more easily than those from dull knives. A sharp knife is a safer knife than a dull knife. less
June 25, 2021
Aria HossainIn physics force=pressure/area. In order to cut food, you have to exert force. According to the equation, force is directly proportional to pressure. A blunt knife has more area around the cutting edge than a sharp knife. So a blunt knife requires more... moreIn physics force=pressure/area. In order to cut food, you have to exert force. According to the equation, force is directly proportional to pressure. A blunt knife has more area around the cutting edge than a sharp knife. So a blunt knife requires more pressure for the same amount of force to be exerted, as the pressure applied increases the chances of the knife slipping and cutting Adam's hand increases. Similarly, a sharp knife would require less pressure to be applied for the same amount of force to be exerted, this not only allows Adam to cut through the food but also prevents the knife from slipping and cutting his hand. less
June 26, 2021
Abdullah JulaybibFirstly, you’ll need more pressure to use a blunt knife.
P=F/A, for a fixed area, force is directly proportional to pressure. If the
area of a blunt and a sharp knife is same, then doubling the pressure on blunt
knife means doubling the force.... moreFirstly, you’ll need more pressure to use a blunt knife.
P=F/A, for a fixed area, force is directly proportional to pressure. If the
area of a blunt and a sharp knife is same, then doubling the pressure on blunt
knife means doubling the force.
Secondly,F= {m(v-u)}/t
Assume, two knives have same mass and you take same amount of time to cut. As
you start from a zero velocity, that means u=0. Ultimately you end up giving
much more velocity to the blunt than sharp one. So, if you accidentally slip
while cutting, blunt will hit your finger faster, which might cause a serious
injury. Sharp knife will have less velocity, which has multiple advantages:
bringing the sharp knife to rest is easier than blunt one. If you slip, sharp
knife won’t hit so fast. It may cause a
little scratch, or you’ll be lucky to stop the sharp knife as soon as it touches your skin (blunt one
would cause a deep scar).
For same time duration, point of contact (finger and knife)
faces two different momenta. As a result,... less
June 26, 2021
Abhay SunnyPressure= force/area, area of sharp knife is less than area of blunt knife, p is proportional to 1/area, so pressure of sharp knife is more than blunt knife.Don't get confused with the wight and pressuring, pressure is the force on a unit area that is... morePressure= force/area, area of sharp knife is less than area of blunt knife, p is proportional to 1/area, so pressure of sharp knife is more than blunt knife.Don't get confused with the wight and pressuring, pressure is the force on a unit area that is help perpendicular whereas weight is the force by which the earth attracts everything towards it's center.
June 27, 2021
Abdullah MasudThis is simply an example of pressure in our daily lives. Here, according to Pascal's law (P = f/a, where pressure is the force applied over a certain area), the sharp knife can exert greater pressure than the blunt knife, as the sharper knife has less... moreThis is simply an example of pressure in our daily lives. Here, according to Pascal's law (P = f/a, where pressure is the force applied over a certain area), the sharp knife can exert greater pressure than the blunt knife, as the sharper knife has less contact area for the same force than the blunt knife, so the force would be exerted over a smaller area. So in order to cut anything, one would need to apply a larger force in a blunt knife than a sharper knife, and this might result in the blunt knife cutting the hand due to excessive pressure applied by the user while cutting any other objects. less
Mr. Ethan was a senior political leader in a village near the Dhaka District. He also used to be a professor of Dhaka University before his political career. He was highly respected in his village community as he did an...
May 11, 2021
Tanveer Tausif RatulMy steps are given below-
Firstly,i will send the young (20-45 years old) back to work instead of the adults, because they face the lowest fatality rate and the lowest need of needing healthcare for COVID-19.But of course,no young boy will be sent for... moreMy steps are given below-
Firstly,i will send the young (20-45 years old) back to work instead of the adults, because they face the lowest fatality rate and the lowest need of needing healthcare for COVID-19.But of course,no young boy will be sent for any difficult and heavy works.As most of the village people do simple works for their living,the young will be a great replacement.
But before sending them to work,i will obviously first vaccinate them by going to everyone's house.They will go to work at 12:01 pm in a day and will finish their work and return home within 6PM.This is because they can complete their studies
in morning before going to work.Moreover,after returning from work, they will be able to get enough time to study and other works.So, i think this process
won't hamper their study system and this will help to keep the wheel of their economy moving. less
May 11, 2021
Tanveer Tausif RatulSecondly,if there is a person in the family of a young man who has a lung infection/other lung diseases,the young of that family who will go to work must be seperated from
them.As every schools and colleges are off now,those buildings are still... moreSecondly,if there is a person in the family of a young man who has a lung infection/other lung diseases,the young of that family who will go to work must be seperated from
them.As every schools and colleges are off now,those buildings are still empty.Therefore,those young going back to work will be temporarily moved to those buildings
and they will be provided with the necessary daily necessities like food,cloth,health care etc.Their will be a guard assigned for 24 hours a day.
Their family members will be able to take food for them but they have to follow proper hygiene rules otherwise they can't enter.Every school and college building
will have one health worker for them who will give free treatment to those young.
The lockdown will be slightly stabilized from 12:00pm to 6pm.Strict lockdown will be maintained for the rest of the time less
May 11, 2021
Yeasin ArafathAs an educated person Mr.Ethan can take some steps to stop spreading covid & to develop
their village economy. He can use his political purpose in this situation also.
In my point of view some ideas are pointed... moreAs an educated person Mr.Ethan can take some steps to stop spreading covid & to develop
their village economy. He can use his political purpose in this situation also.
In my point of view some ideas are pointed below:
1.During lockdown he may arrange online learning & earning programs with younger
& educated village people.It may help their economic condition.
2.He can make a team or organization with young people those who give free service during pandemic such as
village women can work in home(hand crafts,sewing etc.) and they can help to delivering these things.
3.From political background he may manage some reliefs from govt. and distribute those with his organization’s young people.
4.He can make schedules for village farmers when they go to their land to cultivate & collect their vagetables and others seeds by maintaining social distance.
5.He and with the help of young people they can arrange market with maintaining social
distance in the open ground area so that village people can buy... less
May 11, 2021
Taarik HasanAs a Mr. Ethan and a professor and a political leader, I
will use my knowledge from both fields.... moreAs a Mr. Ethan and a professor and a political leader, I
will use my knowledge from both fields.
I will separate the jobs or general people's economic contributions
into three categories: highest, the less, and the least. The main objective is
to keep the economy after reducing the interaction of people.
I will set the time frame for various categories. Before the
office hours on the very morning, the markets will be available for estern
housing (in the evening, the western people will come).
With the office hours, the banks and other related services
will be there. In the evening time, the least contributors will come across
like shopping complexes and restaurants.
At night the manufacturers and agriculture, food services, garments,
suppliers will work.
The statistics on the economic contribution I will follow to
set them at morning, day, or night shifts, related with one another.
People must not leave houses for roaming will be ensured by
political campaigns and creating... less
May 12, 2021
Towhidur R. To combat against covid-19 nothing beats social distancing, closing the borders, and nationwide lockdown. But to reduce the economic backlash certain steps can be taken.
Distribution of workforce could ensure less gathering and reduction of service.... moreTo combat against covid-19 nothing beats social distancing, closing the borders, and nationwide lockdown. But to reduce the economic backlash certain steps can be taken.
Distribution of workforce could ensure less gathering and reduction of service. Businesses will divide the workers into shifts and follow strict guidelines. They will also have to reduce the services they provide and stay open for extra hours. Garments, constructions need to divide their workforce into shifts so it doesn't hinder their work.
Long journeys should be restricted as it increased the chances of spreading the virus. Borders need to stay closed at all costs because new strains are being discovered on a regular basis around the globe and the effects of the mutated virus could be devastating.
Law force should be deployed to monitor unnecessary gatherings and ensure people maintaining the guidelines in public.
The government needs to organize relief funds to ensure infected individuals don't have to go hungry or forced to go... less
May 12, 2021
Khadeeza Afruz ShammeeAlthough the duration and severity of Covid-19 are terrible, it is quite impossible for a country like Bangladesh, to have a long lockdown to sustain the economy. As a policymaker, I will take the following steps :
- I will instruct the industries to... moreAlthough the duration and severity of Covid-19 are terrible, it is quite impossible for a country like Bangladesh, to have a long lockdown to sustain the economy. As a policymaker, I will take the following steps :
- I will instruct the industries to work by dividing the working time into double shifts. In this way, even if the cost of running the industry is a bit higher, the density in the workplace can be avoided.
-Since the marketplaces must be kept open, a family member from each family will be provided a movement pass for shopping at most one day of the week to avoid extra crowds.
-Adequate number of transports would be kept running on the occasion of the upcoming festival so that the passengers can maintain minimum social distance.
-Strict surveillance will be put in place to ensure that people are maintaining proper social distance and hygiene and not leaving their house unnecessarily. Public awareness activities should be carried out to motivate the people to abide by the necessary health norms. less
May 13, 2021
Fatima Ahmed
Thank you for all your answers everybody. We will announce the winner of this quiz tomorrow.