9P Energy Checkpoint 1 Name_____________
1. a) Define energy.
b) State the name and Symbol of the Unit of energy.
2. State the difference between Active Energy & Potential Energy.
3. Give examples of active and potential energy.
Active energy
1.
2.
3.
Potential energy
1.
2.
3.
4. Define “Energy Transformation”.
5. Write the energy transformation diagram that occurs when:
a) a rabbit jumping off a high hill
b) A washing machine is working
c) You eat food and is running 100m competition
d) You turn on the Bunsen burner
6. State the Law of Conservation of Energy.
7. Calculate the gravitational potential energy (Ep) of the following situations (Ep = mgh, g=10 ms-2), remember using FWAU.
a) A person with a mass of 84 kg standing on a cliff 13.4 m high.
b) Two students about to go down a water slide sitting on a tire with a combined mass of 147 kg at the top of the slide which is 20.9 m high.
c) Jug A has 500g of water that 11.2 m above the ground, whilst Jug B has 302 g of water that 14.4 m above the ground. Which jug has more Ep?
8. Calculate the kinetic energy (Ek) of the following situations (Ek = 12mv2), remember using FWAU.
d) A lion with a mass of 54 kg is running at speed of 30ms-1
e) A truck with a mass 403 kg is travelling on SH16 subway at a speed of 80 ms-1
f) 150g of a Kea is flying at the sky at 42 ms-1, whilst 302g of a Kākāpo is flying at 56ms-1. Which bird has more Ek?
9. Complete the following table.
Appliance
Input energy (J)
Output energy (J)
Useful and wasteful output energy (J)
Hair dryer
Electrical = 400
Sound = 150
Heat = ___________
Useful = __________
Wasteful = 150
TV
Electrical = __________
Sound = 500
Heat = 800
Light = 1350
Useful = __________
Wasteful = __________
Washing
machine (with
dryer function)
Electrical = 8900
Sound = 500
Heat = 800
Light = __________ Kinetic = __________
Useful = 7200
Wasteful = __________