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

Click For Summary
SUMMARY

The discussion focuses on calculating the gravitational potential energy of an 800 kg roller coaster as it descends from point A to point B, which is 125 ft (38.1 m) lower at a 40.0° angle. The potential energy at point A is calculated using the formula Ug = mgh, resulting in an initial value of 222,561.92 J. However, the calculation of the vertical drop was identified as incorrect, as it mistakenly suggested a height of 44.1 m instead of the correct 38.1 m. The change in potential energy must be recalculated based on the accurate height.

PREREQUISITES
  • Understanding of gravitational potential energy (Ug = mgh)
  • Basic knowledge of trigonometry (specifically sine function)
  • Familiarity with units of measurement (meters and joules)
  • Concept of energy conservation in physics
NEXT STEPS
  • Recalculate gravitational potential energy using the correct height of 38.1 m
  • Explore the implications of energy conservation in roller coaster dynamics
  • Learn about the effects of friction on potential energy calculations
  • Investigate the relationship between angle of descent and energy loss
USEFUL FOR

Physics students, educators, and anyone interested in understanding energy dynamics in mechanical systems, particularly in the context of roller coasters and gravitational potential energy calculations.

closer
Messages
18
Reaction score
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
Everything looks good except your final answer. Redo that calculation.
 
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
 

Similar threads

Replies
8
Views
3K
  • · Replies 15 ·
Replies
15
Views
5K
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
7K
Replies
3
Views
4K
  • · Replies 4 ·
Replies
4
Views
11K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 10 ·
Replies
10
Views
7K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 12 ·
Replies
12
Views
10K