energy

Question 1

is energy ever used up?

Answer 1

no

Question 2

list the 8 energy stores

Answer 2

thermal
kinetic
GPE
EP
chemical
magnetic
electrostatic
nuclear

Question 3

kinetic energy equation

Answer 3

Ek = 0.5mv^2

Question 4

define doing work

Answer 4

transferring energy from one form to another

Question 5

a builder pushes a wheel barrow a distance of 5.0m across flat ground with a force of 50N. how much work was done by the builder

Answer 5

Wd=Fxd
Wd=50N x 5.0N
Wd=250J

Question 6

what is the gravitational field strength?

Answer 6

9.8N/kg

Question 7

define kinetic energy

Answer 7

the energy an object has when its moving at a constant velocity

Question 8

define renewable

Answer 8

resource that won’t run out in our lifetime

Question 9

define conduction

Answer 9

where vibrating particles transfer energy to neighbouring particles

Question 10

define convection

Answer 10

where energetic particles move away from hotter to cooler regions

Question 11

define non-renewable

Answer 11

resource that damages the environment and will run out one day

Question 12

list the three main non-renewable fossil fuels

Answer 12

coal
oil
(natural) gas

Question 13

list the 7 renewable energy sources

Answer 13

sun (solar)
wind
water waves
hydro-electricity
bio-fuel
tides
geothermal

Question 14

explain how energy is transferred as a ball falls to the ground

Answer 14

GPE to kinetic

Question 15

if energy is transferred to an object’s kinetic energy store what happens to its speed?

Answer 15

speed increases

Question 16

what kind of energy store is energy transferred to when you compress a spring

Answer 16

EPE

Question 17

definition of the specific heat capacity of a material

Answer 17

the energy required to raise one kg of the material by one degree Celsius (°C)

Question 18

does a high thermal conductivity mean there is a high rate of energy transfer

Answer 18

yes

Question 19

give 4 ways to prevent unwanted energy transfers in a home

Answer 19

windows and doors
floor insulation
insulating pipes
solid wall insulation

Question 20

define the term system

Answer 20

an object or a group of objects

Question 21

a cyclist allows his bike to roll down a hill without pedalling. he applies his breaks towards the bottom to warm making it come to a stop. applying breaks causes brakes to warm up. describe the energy transfers that have occurred and state the forces doing work that cause each of these energy transfers

Answer 21

• gravitational force does work on bike causing energy to be transferred from the GPE store of the bike to its KE store
• friction force does work between brake pads and wheels causing energy transfer from bikes KE store to thermal store of the brake pads

Question 22

state 2 disadvantages of solar panels

Answer 22

efficiency is low
only produces power in the day