What's New

• 
  Imad Mustafiz commented on Fatima Ahmed's classified listing.

  

  Adam's Brunoise Dice - $5 Physics Quiz

  Adam's Brunoise Dice - $5 physics quiz
   
  
  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...

  • June 21, 2021

  • Sourav Chowhan likes this.
  • 
    Mesbah Abir To 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 Mim A 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

    • June 21, 2021
    • -
    • 1 likes this
  • 
    Khokon Roy The 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 Mustafiz The 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 Hasan In 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 Naowar Imagine 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 Chowhan So 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 Chowhan propositional 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 Chowhan He 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 Alam From 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 Jim The 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 Arafath In 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 Ratul The 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

    • June 23, 2021
    • -
    • 1 likes this
  • 
    Tanveer Tausif Ratul larger.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 Hasan A 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 Shammee Pascal'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 Hossain In 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 Julaybib Firstly, 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 Sunny Pressure= 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 Masud This 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

    • June 27, 2021