# Speeds of the rolling ball at different points in this roller coaster track

• Ineedhelpwithphysics
In summary, the ball is getting faster as it falls, but it can't be at the highest speed yet because it is still accelerating.

#### Ineedhelpwithphysics

Homework Statement
The image is below.
Relevant Equations
Distance/time

For this question i tried to reason with my self that C was the fastest and A was the second fastest. B would be the third fastest and D would be the least fastest since the ball has to go up. I looked up the answer and it says that C is the fastest , B and D are equal, and A is the slowest. How is that possible if A is the slowest even though with D you have to go up. And any time you go up you lose speed.
Thank you for helping.

Ineedhelpwithphysics said:
And any time you go up you lose speed.
What happens to your speed when you go down ?
What happens to your speed when you're on the same level ?

Ineedhelpwithphysics said:
Homework Statement:: The image is below.
Relevant Equations:: Distance/time

I looked up the answer and it says that C is the fastest , B and D are equal, and A is the slowest.
What are the gravitational potential energies (GPEs) at those points on the track, compared to each other? Remember that KE+PE should be constant unless there are losses (like air resistance).

hmmm27 said:
What happens to your speed when you go down ?
What happens to your speed when you're on the same level ?
Yes exactly so how is A the slowest if the ball is going down.

berkeman said:
What are the gravitational potential energies (GPEs) at those points on the track, compared to each other? Remember that KE+PE should be constant unless there are losses (like air resistance).
I didn't learn gravitational potential energies I am in chapter 3 of paul hewitts conceptual physics book.

Ineedhelpwithphysics said:
hmmm27 said:
Ineedhelpwithphysics said:
any time you go up you lose speed.
What happens to your speed when you go down ?
What happens to your speed when you're on the same level ?
Yes exactly so how is A the slowest if the ball is going down.
"Yes exactly" to what ? exactly.

The problem says "released", not "shoved", "pushed" or "shot". At point "O" its speed is zero. Do things slow down the farther they fall ?

Also, the problem is meant to be envisioned/answered without consideration for friction forces ; the ball's speed isn't being affected by the air and it's not rubbing against the track.

Last edited:
Ineedhelpwithphysics said:
Yes exactly so how is A the slowest if the ball is going down.
Going down means it is getting faster, not that it is already fast. And it can't be at the highest speed yet if it is still accelerating.

## 1. What factors affect the speed of a rolling ball on a roller coaster track?

The speed of a rolling ball on a roller coaster track is affected by several factors, including the height of the track, the angle of the track, the weight of the ball, and the amount of friction between the ball and the track.

## 2. How does the height of the track affect the speed of the rolling ball?

The higher the track, the greater the potential energy of the ball. As the ball rolls down the track, this potential energy is converted into kinetic energy, increasing the speed of the ball.

## 3. Why does the ball slow down at certain points on the track?

The ball slows down at certain points on the track due to the effects of friction. As the ball rolls, it experiences friction from the track, which converts some of its kinetic energy into heat. This causes the ball to slow down.

## 4. How does the angle of the track affect the speed of the rolling ball?

The steeper the angle of the track, the greater the acceleration of the ball. This is due to the force of gravity pulling the ball down the track at a faster rate.

## 5. Can the speed of the rolling ball be calculated at any point on the track?

Yes, the speed of the rolling ball can be calculated at any point on the track using the principles of conservation of energy and Newton's laws of motion. By knowing the height, angle, and other factors, the speed of the ball can be determined at any point on the track.