P 1.1 Energy

Question 1

What is a system?

Answer 1

A system is the single object or a group of objects you’re interested in

Question 2

What are the 8 energy stores?

Answer 2

Kinetic
Gravitational potential
Chemical
Elastic potential
Magnetic
Electrostatic
Nuclear
Thermal

Question 3

Give an example of something with chemical energy

Answer 3

Fuels, food, batteries

Question 4

Give an example of something with kinetic energy

Answer 4

Anything that moves: cars, running, ball rolling, etc

Question 5

Give an example of something with gravitational potential energy

Answer 5

Anything raised above ground level

Question 6

Give an example of something with elastic potential energy

Answer 6

Anything stretched, e.g. springs and rubber bands

Question 7

Give an example of something with magnetic potential energy

Answer 7

Two magnets attracting or repelling each other

Question 8

Give an example of something with electrostatic energy

Answer 8

Two charges that attract or repel each other

Question 9

Give an example of something with nuclear energy

Answer 9

The nucleus of an atom releases energy from this store in nuclear reactions

Question 10

Give an example of something with Thermal energy

Answer 10

A hot water bottle. The hotter the object, the more energy in the store

Question 11

How is energy transferred?

What are the four pathways?

Answer 11

Mechanically
Electrically
Heating
Radiation

Question 12

What is the conservation of energy?

Answer 12

Energy can be transferred, stored or dissipated but can never be created or destroyed.

Question 13

What is useful energy?

Answer 13

Energy that is transferred to an energy store that we did want

Question 14

What is wasted energy?

Answer 14

Energy that is transferred to an energy store that we didn’t want.

Question 15

What happens to the wasted energy of a light bulb?

Answer 15

Heats the air around it / surroundings

Question 16

How can you reduce unwanted energy transfers?

Answer 16

Lubricate to reduce friction

Insulate to reduce heat loss to the surroundings

Question 17

How do you calculate efficiency?

Answer 17

Efficiency = Useful energy / Total energy

Question 18

What is thermal conductivity?

Answer 18

How much energy is transferred by a material.
A material with a high thermal conductivity transfer lots of energy in a short time.
A material with a low thermal conductivity are called thermal insulators.

Question 19

What is work done?

Answer 19

The total amount of energy transferred

Question 20

What is the equation the links work done, force and distance?

Answer 20

Work done = Force x distance

Question 21

What is the equation for gravitational potential energy?

Answer 21

gravitational potential energy = mass x gravity x height

Question 22

What is the equation for kinetic energy?

Answer 22

kinetic energy = 1/2 x mass x velocity^2

Question 23

How is energy converted when a ball drops?

Answer 23

Gravitational potential energy of the high ball is converted to kinetic energy as the ball falls.

Question 24

What is the formula for elastic potential energy?

Answer 24

Elastic potential energy = 1/2 x spring constant x extension ^2

Question 25

What is the limit of proportionality e.g. for a spring?

Answer 25

The point at which if you carry on pulling it, it will stretch and not go back to its original shape

Question 26

How does the spring constant relate to how easily a spring can be stretched?

Answer 26

The larger the spring constant the stiffer the spring and the more difficult it is to stretch.