Change in potential energy on a roller coaster drop (frictionless)

In summary, the potential energy at point A is 222561.92 J, and the change in potential energy as the coaster moves is unknown due to the incorrect calculation of the potential energy at point A.
  • #1
closer
18
0
800 kg roller coaster is initially at the top of a rise, at point A. It then moves 125 ft (38.1 m), at an angle of 40.0° below the horizontal, to a lower point, B.

(a) Choose point B to be the zero level for gravitational potential energy. Find the potential energy of the roller coaster-Earth system at points A and B and the change in potential energy as the coaster moves.

To start, I aimed to find the potential energy at point A:
Ug = mgh
Ug = (800)(9.8)(y component of h)
Ug = (800)(9.8)(38.1sin40)
Ug = 222561.92 J

What am I missing in my process? Thanks in advance.
 
Physics news on Phys.org
  • #2
Everything looks good except your final answer. Redo that calculation.
 
  • #3
closer said:
800 kg roller coaster is initially at the top of a rise, at point A. It then moves 125 ft (38.1 m), at an angle of 40.0° below the horizontal, to a lower point, B.

(a) Choose point B to be the zero level for gravitational potential energy. Find the potential energy of the roller coaster-Earth system at points A and B and the change in potential energy as the coaster moves.

To start, I aimed to find the potential energy at point A:
Ug = mgh
Ug = (800)(9.8)(y component of h)
Ug = (800)(9.8)(38.1sin40)
Ug = 222561.92 J

What am I missing in my process? Thanks in advance.

I think your vertical drop calculation is in error. Your answer suggests the original height was 44.1m when the problem says it was 38.1m
 

FAQ: Change in potential energy on a roller coaster drop (frictionless)

1. How does the change in potential energy on a roller coaster drop affect its speed?

The change in potential energy on a roller coaster drop is directly related to its speed. As the roller coaster drops, it loses potential energy and gains kinetic energy, which causes it to speed up.

2. Is the change in potential energy on a roller coaster drop affected by friction?

No, the change in potential energy on a roller coaster drop is not affected by friction as long as the roller coaster is frictionless. This is because friction converts some of the potential energy into heat, resulting in a loss of energy.

3. How does the height of the drop affect the change in potential energy on a roller coaster?

The height of the drop directly affects the change in potential energy on a roller coaster. The higher the drop, the greater the change in potential energy and the faster the roller coaster will go.

4. How does the mass of the roller coaster train affect the change in potential energy on a roller coaster drop?

The mass of the roller coaster train does not affect the change in potential energy on a roller coaster drop. This is because potential energy is dependent on the height of the drop and the force of gravity, which are independent of the mass of the object.

5. Can the change in potential energy on a roller coaster drop be negative?

Yes, the change in potential energy on a roller coaster drop can be negative if the roller coaster is traveling uphill. In this case, the roller coaster is gaining potential energy and losing kinetic energy, resulting in a negative change in potential energy.

Back
Top