# Calculating Frictional Force on a Roller Coaster: Solving for Final Velocity

• Claire
In summary, the conversation discusses a physics quiz question involving a roller coaster on a hill with an initial velocity, length and angle given. The coefficient of friction is also provided and the task is to find the final velocity. The conversation includes discussions about relevant equations, the need for mass and acceleration, and the importance of finding forces and considering work done. Ultimately, the person asking for help was able to figure out the answer.
Claire

## Homework Statement

Ok so there was a question on a physics quiz I did that I have no idea how to answer. There was a roller coaster going down a hill with an initial velocity of 1.67m/s. The hill is 60m long and had an angle of 40 degrees. There is a coefficient of friction of 0.100 with the roller coaster. We had to find the final velocity

Ff=uFn
F=ma
d=vot + 1/2at2

## The Attempt at a Solution

I honestly had no idea what to do for this question. I assume it had something to do with the x and y components of velocity, but I feel like you need mass or acceleration to answer this question and I don't know how to relate velocity to friction.

Last edited by a moderator:
Can you post your free body diagram please. By the way, welcome to Physics Forums.

Claire said:
something to do with the x and y components of velocity
Not really.
Claire said:
you need mass
When a problem like this does not provide mass, either as a definite value or as an unknown allowed in the answer, it is a fair bet that it does not matter what the mass is. Just create an unknown, m, for it and expect it to cancel out later.
Claire said:
or acceleration
It can be done that way, but you do not need to find the acceleration.
Find the forces, then think about work done.

Thank you to everyone who offered to help, I figured out the answer!

## 1. What is the definition of force of friction?

The force of friction is the resistance force that occurs when two surfaces come into contact and slide or attempt to slide against each other.

## 2. How is the force of friction calculated?

The force of friction is calculated by multiplying the coefficient of friction (a measure of how rough or smooth the surfaces are) by the normal force (the force pressing the two surfaces together).

## 3. What factors affect the force of friction?

The force of friction is affected by the roughness of the surfaces, the weight of the object pressing against the surfaces, and the type of material the surfaces are made of.

## 4. How does the force of friction influence an object's motion?

The force of friction acts in the opposite direction of an object's motion, slowing it down and eventually bringing it to a stop.

## 5. How can the force of friction be reduced?

The force of friction can be reduced by using lubricants, making the surfaces smoother, or by reducing the weight of the object pressing against the surfaces.

• Introductory Physics Homework Help
Replies
2
Views
1K
• Introductory Physics Homework Help
Replies
10
Views
4K
• Introductory Physics Homework Help
Replies
15
Views
5K
• Introductory Physics Homework Help
Replies
9
Views
780
• Introductory Physics Homework Help
Replies
3
Views
6K
• Introductory Physics Homework Help
Replies
15
Views
1K
• Introductory Physics Homework Help
Replies
1
Views
1K
• Introductory Physics Homework Help
Replies
3
Views
2K
• Introductory Physics Homework Help
Replies
1
Views
3K
• Introductory Physics Homework Help
Replies
4
Views
3K