P3h: The energy of games and theme rides

Question 1

Describe Gravitational Potential Energy (GPE)

Answer 1

tored energy that something has because of its position in a gravitational field

Question 2

GPE Equation

Answer 2

Change in GPE (J) = Mass(Kg) x Gravitational field strength (N/Kg) x Change in height (m)

Question 3

Describe the energy transfer for a body falling through the atmosphere at terminal speed (3)

Answer 3

GPE usually transferred to KE when something falls

at terminal speed, speed can’t increase so KE does not increase

GPE transferred to increase internal or thermal energy of surrounding air particles through the mechanism of friction

Question 4

Describe a gravity ride (roller-coaster) in terms of kinetic energy (KE), gravitational potential energy (GPE) and energy transfer(4)

Answer 4

at top, carriage has maximum GPE, minimum KE

as it descends, GPE transferred to KE, +speed

at lowest point, KE is maximum, GPE is minimum

as it ascends, KE is transferred to GPE, -speed

Question 5

Describe the effect of changing mass and speed on KE (2)

Answer 5

doubling mass doubles KE

doubling speed quadruples KE

Question 6

GPE to KE equation and rearrangement (3)

Answer 6

KE gained = GPE lost;

1/2mv^2 = mgh

h = v^2 / 2g (mass cancels out); can be used to find the height something needs to fall from to reach a certain speed
(e.g. for a roller-coaster)

Question 7

Why is each peak lower than the one before(3)

Answer 7

Some energy is transferred to heat and sound due to friction and air resistance
-GPE at top = KE at bottom + energy transferred(to heat and sound) due to friction