[Physics] questions/equations, physics 11

[anqel]

Looking for someone to help me Im having trouble with Friction, equations in physics 11.

IE. To slide a metal puck across a greased sheet of metal at constant speed requires a force of 0.525 N. If the force of gravity on the puck is 5.00 N, what is the coefficient of friction between the puck and the greased metal?

If anyone can help, i know its kinda simple, but i would appreciatte it alot

 

[Koot]

First draw a free body diagram and label the forces.

There's 4 here: Force, friction, gravity, and normal.

Then you can set the forces that face the same axes equal the ma. Same with the others and you have a set of equations you can use to find the coefficient.

 

[malyce]

What is the mass of the puck?

 

[iWoodKart]

@Malyce:Force due to gravity is 5 Newtons.. This makes the mass 5/9.81 kg. Mass not need as moving at constant speed(newtons second law)

To work this out you need to overcome the friction force for the puck to move at a constant speed(ie acceleration is zero). Use sum(forces)=ma.

The two forces that are of importance are the force of 0.525N and the frictional force(friction_force=μN) where μ is friction coefficient and N the normal reaction force.

summing the forces:
0.525-friction_force=ma (right side=0 due to constant speed(0 acceleration))
0.525-μN=0
μ=0.525/5

so μ=0.105

 

[anqel]

Wow tyvm, i know im in college studying this stuff lol, but nice to see diffrent ways of putting it tyvm <3