The energy of games and theme rides Flashcards
1
Q
What has gravitiational potenial energy?
A
An object held above the ground has gravitiational potenial energy.
2
Q
m =
A
Mass
3
Q
h =
A
vertical height moved
4
Q
g =
A
gravitational field strength (10 N/kg)
5
Q
GPE unit
A
Joules (J)
6
Q
What does GPE equal?
A
GPE = mgh
7
Q
What does a bouncing ball do?
A
The bouncing ball converts gravitational potential energy to kinetic energy and back to gravitational potential energy. It does not return to its original height because energy is transferred.
8
Q
Stages of ball bouncing
A
- The ball has gravitational
9
Q
What happens when a parachutist reaches terminal speed?
A
- When skydivers reach terminal speed, their kinetic energy has a maximum value and remains constant. The gravitational potential energy lost as they fall is used to work against friction (air resistance).
- When terminal speed is reached it can be shown as:
- change in GPE = I work done against friction
10
Q
How does a roller coaster work?
A
- A roller coaster uses a motor to haul a train up in the air. The riders at the top of a roller coaster ride have a lot of gravitational potential energy.
- When the train is released it converts gravitational potential energy to kinetic energy as it falls. This is shown in the formula:
- gravitational potential energy (GPE) = gain in kinetic energy (KE)
- Ignoring friction, as the train falls:
- mgh = ½mv2
- h = mv2/2mg = v2/2g
- So this is independent of the mass of the falling object.
11
Q
A
- Each peak is lower than the one before because some energy is transferred to heat and sound due to friction and air resistance.
- This is shown by the formula:
- GPE at top = KE at bottom + energy transferred (to heat and sound) due to friction.
12
Q
If speed doubles.
A
KE quadruples (KE ∝ v2)
13
Q
If mass doubles
A
KE doubles (KE ∝ m)
