A calculation on thermal energy from friction.

In summary, to calculate the amount of heat generated from friction in a fictional scenario of a knife sliding across a person's chest with high pressure but no damage, you need to know the coefficient of friction and the normal force, and use the formula Heat = Coefficient of Friction x Normal Force x Distance to calculate it.
  • #1
Physics quest
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Hello, I am new here and I joined because I was wondering if I could find any help concerning finding heat from friction.

The question is fictional, I am not talking about something that has happened, but I am interested in a realistic calculation for the physics behind it.

in my problem, a guy slashes somebodies chest with a weapon, say a sharp instrument like a knife tip but the guys chest is incredible dense, it just slides off. The slash comes from right to left across the torso, no damage occurs but the guy getting striked gets knocked back.

The guy doing the striking has a ridiculous pressure of about 1 billion bar on the tip of the knife which slides an inch or so before coming free without causing any damage.

My question is, how much heat would be created at the tip of the knife as it slides across the other guys bare chest? without cutting it with these pressures? I imagine I need the coefficent of friction on skin, I have the force in Newtons (3.9mega Newtons) in the guys arm/body doing the slashing.

Is this possible to calculate? thanks to any answers.
 
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  • #2
To calculate the amount of heat generated from friction, you need to know the coefficient of friction, which is the ratio between the force required to move two surfaces in contact with each other and the normal force pressing them together. You also need to know the normal force, which is the force applied perpendicular to the surface when two objects are in contact. Once you have these two pieces of information, you can use the formula Heat = Coefficient of Friction x Normal Force x Distance. You can then plug in your values for coefficient of friction, normal force, and distance to calculate the heat generated.
 

1. What is thermal energy?

Thermal energy is the energy that is generated by the movement of particles within a substance. It is a form of kinetic energy and is related to the temperature of an object.

2. How is thermal energy related to friction?

Friction is the resistance that occurs when two objects rub against each other. The friction between two surfaces causes heat to be generated, which converts into thermal energy.

3. How is thermal energy calculated from friction?

The calculation of thermal energy from friction involves determining the amount of heat that is generated due to friction. This can be done using the formula Q = μNΔx, where Q is the heat produced, μ is the coefficient of friction, N is the normal force, and Δx is the displacement of the object.

4. What are some real-life examples of thermal energy from friction?

Some common examples of thermal energy from friction include rubbing your hands together to warm them up, the heat generated by car brakes when they are applied, and the heat produced by a pencil when it is sharpened.

5. How is thermal energy from friction used in practical applications?

Thermal energy from friction is used in various practical applications, such as in engines where the heat generated by friction is converted into mechanical energy to power the vehicle. It is also used in industrial processes, such as welding and cutting, where the friction between materials produces the necessary heat.

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