P1 Energy and Conservation

Question 1

what is elastic potential?

Answer 1

the amount an object can be stretched while returning to its original form.

Question 2

what is kinetic energy?

Answer 2

the rate at which objects move and their mass.

Question 3

what is nuclear energy?

Answer 3

energy stored in the nuclei of an atom.

Question 4

what is G.P.E?

Answer 4

the amount of energy at a certain height

Question 5

what is thermal energy?

Answer 5

the total kinetic energy and potential energy that cause vibrations.

Question 6

what is chemical energy?

Answer 6

the energy stored in chemical bonds

Question 7

what is magnetic and electrostatic energy?

Answer 7

the store between repelling and attracting poles

Question 8

what is the law of energy?

Answer 8

energy cannot be created or destroyed

Question 9

what are the four energy transfers?

Answer 9

mechanical, electrical, heat and radiation

Question 10

what is a closed system?

Answer 10

an object or group of objects in which no energy transfers can take place out or in the energy stores, only can be transferred to different stores within the system.

Question 11

what is equivalent to work done?

Answer 11

energy transferred

Question 12

what is the formula for work done?

Answer 12

work done (J)= force applied (J) x distance (m)

Question 13

what opposes work done?

Answer 13

friction opposes work done, and is transferred into thermal energy

Question 14

what is the formula for the change in G.P.E?

Answer 14

change in G.P.E (J) = mass (kg) x gravitational field strength (N/kg) x height (m)

Question 15

what is the earth’s gravitational field strength?

Answer 15

9.8 N/kg

Question 16

what is the formula for elastic potential?

Answer 16

elastic potential (J) = 1/2 x spring constant (N/m) x extension2 (m)

Question 17

what happens to useful energy?

Answer 17

it’s transferred into the form wanted

Question 18

what happens to wasted energy?

Answer 18

it’s not usefully transferred

Question 19

what happens when energy is transferred into the surroundings?

Answer 19

it’s warmed up and dissipated

Question 20

what happens if energy is dissipated further?

Answer 20

it becomes harder to use for further transfers, usually due to friction

Question 21

what is input energy?

Answer 21

the energy supplied to a machine

Question 22

how can energy be wasted?

Answer 22

friction, air resistance and electrical resistance meaning no machine can be fully efficient

Question 23

how can machines be made more efficient?

Answer 23

using lubricant to reduce friction, making machines more streamlined and using copper wires

Question 24

what is the formula efficiency?

Answer 24

efficiency = useful energy transferred/ total energy supplied x 100

Question 25

how is energy supplied to homes?

Answer 25

through gas and oil, through heating

Question 26

what is power?

Answer 26

the rate at which energy is transferred

Question 27

what is 1kW in watts?

Answer 27

1000 watts

Question 28

what is 1mW?

Answer 28

1,000,000 watts

Question 29

what is a formula for power?

Answer 29

work done (J) or energy transferred/ time taken (s)

Question 30

what is another formula for power?

Answer 30

current (A) x p.d (v)

Question 31

formula for power wasted?

Answer 31

total power - useful power or efficiency x input power