Coefficient Of Kinetic Friction

In summary, by using the equations v=u+at and v^2-u^2=2aS, and applying the concept of conservation of energy with the equation (1/2)*m*v^2=u*m*g*S, we can determine the coefficient of kinetic friction between the hockey puck and ice. The calculation yields a value of (1/2)v^2/S*g, which should provide the correct answer.
  • #1
Joshw17_15
3
0
A hockey puck on a frozen pond is given an initial speed of 20.0 m/s. If the puck always
remains on the ice and slides 115 min before coming to rest, determine the coefficient of
kinetic friction between the puck and ice.




[v = u + a*t
=> 0 = 20 - a* 115*60
=> a = 20/(115*60)

v^2 - u^2 = 2*a*S
=> S = 400*(115*60)/2*20



(1/2)*m*v^2 = u*m*g*S
=> u = (1/2)*v^2/S*g
=> u = (1/2) * 400/S*9.8

I use these equations and I can't seem to come up with right answer
 
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  • #2
Joshw17_15 said:
(1/2)*m*v^2 = u*m*g*S
=> u = (1/2)*v^2/S*g
=> u = (1/2) * 400/S*9.8

I use these equations and I can't seem to come up with right answer

This should give the correct answer.

1/2mv2=μmg(115)
 

FAQ: Coefficient Of Kinetic Friction

1. What is the coefficient of kinetic friction?

The coefficient of kinetic friction is a measure of the amount of resistance between two surfaces in motion. It is represented by the symbol μk and is a dimensionless value between 0 and 1.

2. How is the coefficient of kinetic friction calculated?

The coefficient of kinetic friction is calculated by dividing the force of kinetic friction by the normal force. This can be represented by the equation μk = Fk/Fn, where Fk is the force of kinetic friction and Fn is the normal force.

3. What factors affect the coefficient of kinetic friction?

The coefficient of kinetic friction can be affected by several factors, including the nature of the surfaces in contact, the roughness of the surfaces, the amount of force applied, and the presence of lubricants or other substances between the surfaces.

4. How does the coefficient of kinetic friction differ from the coefficient of static friction?

The coefficient of kinetic friction measures the resistance between two surfaces in motion, while the coefficient of static friction measures the resistance between two surfaces at rest. The coefficient of static friction is typically higher than the coefficient of kinetic friction for the same two surfaces.

5. Why is the coefficient of kinetic friction important?

The coefficient of kinetic friction is important because it helps to determine the amount of force needed to keep an object in motion or to overcome the resistance of a surface. It is also used in various engineering and scientific applications, such as designing brakes for vehicles and determining the efficiency of machines.

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