energy

Question 1

power

Answer 1

When work is done on an object, energy is transferred. The
rate
at which this energy is transferred

Question 2

efficiency

Answer 2

The efficiency is the ratio of the useful work done by a machine, engine, device, etc, to the
energy supplied to it,

Question 3

renewable energy souces

Answer 3

Biofuel
- Wind
- Hydro-electricity
- Geothermal
- Tidal
- Solar
- Water waves

Question 4

8 energy stores

Answer 4

Chemical
Kinetic
Gravitational potential
Elastic potential
Magnetic
Electrostatic
Nuclear
Internal (thermal)

Question 4

non-renewable energy resources

Answer 4

Fossil Fuels (coal, oil, gas)
- Nuclear Fuel

Question 5

4 pathways

Answer 5

force, electricty, light, heat

Question 6

Write down the correct answer to complete the statement.
Energy can not…

Answer 6

be transferred from one source to another.

Question 7

Name the energy sources for:
i Input energy
ii Useful output energy
iii Wasted output energy.

Answer 7

i Input energy Chemical (Coal)

ii Useful output energy Electrostatic (Electric current)

iii Wasted output energy. Thermal (Waste heat)

Question 8

When a football is kicked it gains kinetic energy.
a. What is the formula used to calculate kinetic energy?

Answer 8

Ek
= ½ m v2

Question 9

what is a conductor

Answer 9

A conductor is a material that allows internal (thermal) energy
to be transmitted through it easily.

Question 10

All metals are good c________. When one end of a metal rod is put into a fire, the e_______ from the flame makes the
ions
in the rod v_____ faster. Since the ions in the solid metal are close together, this increased
v_______
means that they c______ with neighbouring i___ more frequently. Energy is passed on through the metal by these c_______, t_________ the energy. More frequent collisions increase the
r___
of transfer

Answer 10

All metals are good conductors. When one end of a metal rod is put into a fire, the energy from the flame makes the
ions
in the rod vibrate faster. Since the ions in the solid metal are close together, this increased
vibration
means that they collide with neighbouring ions more frequently. Energy is passed on through the metal by these collisions, transmitting the energy. More frequent collisions increase the
rate
of transfer

Question 11

What is an insulator

Answer 11

An insulator is a material that will not allow the easy flow of energy.

Question 12

What is dissipation

Answer 12

ways in which energy is wasted

Question 13

In what ways can energy be dissipated

Answer 13

heat, sound

Question 14

How much kinetic energy does a 30 kg dog have when it runs at 4 m/s?

Answer 14

Ek = 1/2 mv^2
1/2 x 30 x 16
240J

Question 15

what is work

Answer 15

the measure of energy transfer when a force (F) moves an object through a distance (d).

Question 16

energy transferred = ?

Answer 16

energy transferred = work done

Question 17

equation used to calculate the work done

Answer 17

work done = force × distance