# Physics-11

posted by .

A 12 kg object is at the top of a 41 degree inclined ramp. It is released and it reaches the bottom of the 85 m ramp in 2.3 seconds. what is the force of friction between the object and the ramp? What is the coefficient of friction?

Can someone help me do this?

• Physics-11 -

Here's a quick way to do it using energy. The average velocity during the descent is 85/2.3 = 36.96 m/s. The final velocity is twice that, or
Vf = 73.91 m/s.
Final kinetic energy at the bottom = (M/2)Vf^2 = 32778 J

Potential energy loss at the bottom =
M*g*Lsin41 = 35859 J

Energy lost to friction = 3081 J

Since Work = Force x Distance, the friction force is
Ff = 3081J/85m = 36.2 N

That friction force, the weight and ramp angle can be used to get the friction coefficient, Mu.

Ff = M g cos41 *Mu

## Similar Questions

You're given a ramp 0.5m in height with a 3m incline. A mass of 1kg is at the top of the ramp and there is a friction of 2N. If the ramp has a force of friction of 2N, what will the speed at the bottom of the ramp be?
2. ### physics

a 50kg object is suspended by a rope over a pulley which is connected to a large mass of 61.3kg. The mass rests on a 30 degree inclined ramp. The coefficient of kinetic friction between the block and the ramp is .15. What is the 50kg …
3. ### Physics

A 12 kg object is at the top of a 41 degree inclined ramp. It is released and it reaches the bottom of the 85 m ramp in 2.3 seconds. what is the force of friction between the object and the ramp?
4. ### Physics

An object m is released from the top of an inclined, frictionless plane that is inclined at angle theta with the horizontal. The top of the ramp has height h. Which of the following would change the acceleration of the object if it …
5. ### Intro to Physics

A uniform hoop and a disk, having the same mass and the same radius, are released simultaneously from rest at the top of a ramp. Which object reaches the bottom of the ramp first?
6. ### physics mechanical energy

A skateboarder with mass ms = 42 kg is standing at the top of a ramp which is hy = 3.7 m above the ground. The skateboarder then jumps on his skateboard and descends down the ramp. His speed at the bottom of the ramp is vf = 6.3 m/s. …
7. ### physics

Starting from rest, a 10kg suitcase slides down a 3.00m long ramp inclined at 30 degrees from the floor. The coefficient of friction between the suitcase and the ramp is 0.35. 1) what net force is applied to the suitcase while it is …
8. ### Physics

Starting from rest, a 10.0 Kg suitcase slides down a 3.00m long ramp inclined at 30.0 degrees from the floor. The coefficient of friction between the suitcase and ramp is .35. A: what net force is applied to suitcase while it is on …
9. ### Science Psysics

A 6 kg black is placed at the very top of a ramp that is inclined at 31 degrees and the block is released to slide down the ramp. As the block slides friction exerts a constant resistive force of 17N directed back up the ramp What …
10. ### physics (simple question)

How does increasing the degree of a ramp change the an object's motion. the object is at the bottom and isn't going to go off the ramp. The object has an initial velocity.

More Similar Questions

Post a New Question