Energy part 1

Question 1

What is a system ?

Answer 1

A system is an object or a group of objects .

Question 2

What do systems have ?

What is energy measured in?

Answer 2

Systems have energy .

Energy is measured In Joules.

Question 3

What cannot happen to energy ?what can happen to energy ?

Answer 3

Energy can not be created or used up or destroyed.

Energy can only be stored or transferred.

Question 4

Where is energy stored ?

When is energy transferred ?

Answer 4

Energy is stored in different
energy stores .
Energy is transferred when a system changes .

Question 5

What is the amount of energy transferred called ?

Answer 5

The amount of energy transferred is called “work done”

Question 6

What is the most common misunderstanding about energy ?

Answer 6

There aren’t different types of energy, just different ways of storing it.

Question 7

What are examples of different energy stores ?

7 examples

Answer 7

Energy can be found in different stores: chemical, elastic potential, electrostatic, gravitational potential, kinetic, magnetic, nuclear

Question 8

Where do all objects have energy ?

What does this not apply to ?

Answer 8

All objects have energy in their thermal energy store (unless they are at a temperature of absolute zero).

Question 9

How can objects have more energy in their thermal energy store ?

Answer 9

Objects have more energy in their thermal energy store when their temperature rises.

Question 10

How can Objects have energy in their gravitational potential energy store?

Answer 10

Objects raised against the pull of gravity have energy in their gravitational potential energy store.

Question 11

How can objects have chemical energy store?

Where do moving objects have energy in ?

Answer 11

Objects with chemical bonds have energy in their chemical energy store.
Moving objects have energy in their kinetic energy store

Question 12

How can you have elastic potential energy?

Answer 12

Objects being stretched or squashed have energy in their elastic potential energy store.

Question 13

How can you have energy in magnetic energy store?

Answer 13

When magnetic materials attract or repel each other they have energy in their magnetic energy store

Question 14

How can you have electrostatic energy store ?

Answer 14

When charged particles attract or repel each other they have energy in their electrostatic energy store

Question 15

How can you have nuclear energy store?

Answer 15

Atomic nuclei have energy in their nuclear energy store.

Question 16

What happens when a system changes in witch direction ?

Answer 16

When a system changes energy is transferred.

Energy may be transferred in different directions.

Question 17

3 main ways energy can be transferred .

Answer 17

1) Energy can be transferred into or out of a system.
2) Energy can be transferred between different objects in a system.
3) Energy can also be transferred between different energy stores.

Question 18

What happens when a person throws a ball upwards ?

Answer 18

For example, when a person throws a ball upwards their arm is doing work.

Question 19

👉When a person throws a ball upwards how is energy being transferred ?

Answer 19

First, energy is transferred from their arm’s chemical energy store to their arm’s kinetic energy store.

Question 20

👉Then how is the energy transferred ?

Answer 20

Then energy is transferred from the arm’s kinetic energy store to the ball’s kinetic energy store.

Question 21

Then what happens as the ball moves upwards?

Answer 21

As the ball moves upwards, it slows down under the downwards force of gravity.

Question 22

So what happens to the energy as the ball is moving upwards ?

Answer 22

So, energy is transferred from its kinetic energy store to its gravitational potential energy store.

Question 23

What happens at the balls highest point ?

Answer 23

At its highest point it stops for a moment, this is the point all the energy has been transferred to the gravitational potential store.

Question 24

What happens to the energy as the ball falls ?

Answer 24

As it falls again, the energy from the gravitational potential store is transferred back to the kinetic store.

Question 25

What is the equation for kinetic energy ?

In words and formula

Answer 25

1 2
E = — mv
2

                           1                              2 Kinetic energy = ——  x mass x speed   (J)                        2

Question 26

How can an object have more Kinetic energy ?

Answer 26

Heavier, faster objects have more kinetic energy than lighter, slower objects.

Question 27

What is the equation for elastic potential energy ?

Answer 27

1 2
E =— ke
2

                                             1 Elastic potential energy(J) = — x spring 
                                             2 constant (N/m) x extension (m)

Question 28

What is the spring extension ?

Answer 28

The spring’s extension is the difference between its stretched length and its original length.

Question 29

What does the spring constant tell you ?

Answer 29

The spring constant tells you how difficult it is to stretch the spring.

Question 30

What happens the more a string is stretched ?

Answer 30

The more a spring is stretched, the more elastic potential energy it stores.

Question 31

When does the elastic potential energy equation work ?

Answer 31

This equation only works if the limit of proportionality has not been exceeded

Question 32

What is the limit of proportionality ?

Answer 32

This is the point at which the spring’s extension is no longer proportional to the force stretching it.

Question 33

What does stretched springs store ?

Answer 33

Stretched springs store elastic potential energy

Question 34

What does an objects kinetic energy depend on ?

Answer 34

The amount of energy in an object’s kinetic energy store depends on its mass and speed

Question 35

Where is energy transferred ?

Answer 35

Energy can be transferred in different directions

Question 36

What energy stores do objects have ?

Where is energy stored ?

Answer 36

Objects have different energy stores.

Energy is stored in a system.

Question 37

What is the equation for gravitational potential energy ?

Answer 37

E=m x g x h

Gpe=mass(kg) x gravitation field strength (N/Kg)x height(m)

Question 38

What does gravitation field strength depend on ?

Answer 38

Gravitational field strength depends on the mass of the planet the object is on.

Question 39

What is the gravitational field strength on earth ?

Answer 39

On Earth, the gravitational field strength is 9.8 N/kg.

Question 40

What does this mean calculations for objects on earth will be ?

Answer 40

This means calculations for objects on Earth will always use 9.8 N/kg.

Question 41

How can an object gain more gravitational potential energy ?

Answer 41

The higher an object is above ground level, the more gravitational potential energy it stores.