P1- Conservation And Dissipation Of Energy

Question 1

What is energy?

Answer 1

The capacity of something to do work.

Question 2

What happens if something contains a story of energy?

Answer 2

It is able to do work.

Question 3

What is the law of conservation of energy?

Answer 3

‘Energy cannot be created or destroyed only stored or transferred.’

Question 4

What is kinetic energy?

Answer 4

The energy of a moving object.

Question 5

What is gravitational energy?

Answer 5

The energy something gains when you lift it up and which it loses when it falls.

Question 6

What is elastic energy?

Answer 6

The energy of a stretched spring or electric band.

Question 7

What is magnetic energy?

Answer 7

The energy due to the force of attraction (or repulsion) between two charges

Question 8

What is electrostatic energy?

Answer 8

The energy due to their e of attraction (or repulsion) between two charges.

Question 9

What is chemical energy?

Answer 9

The energy contained in a chemical substance.

Question 10

What is nuclear energy?

Answer 10

The energy contained within the nucleus of an atom.

Question 11

What is thermal energy?

Answer 11

The energy something has due to its temp or state.

Question 12

What is mechanical energy transfer?

Answer 12

When a force acts on a body energy can be transferred between two stores.

Question 13

What is electrical energy transfer?

Answer 13

Electricity can transfer energy from a power source delivering it to components within a circuit.

Question 14

What is a heat energy transfer?

Answer 14

Thermal energy can be transferred from place to place by the processes of conduction convection and thermal radiation.

Question 15

What is radiation energy transfer?

Answer 15

Light and sound carry energy and so can transfer between places.

Question 16

What one thing is pointed out from the law of conservation of energy?

Answer 16

A close system (a region a group of objects from which nothing can enter or escape) the total amount of energy is constant.

Question 17

What energy transfer would occur from a moving object hitting an obstacle? For example a car hitting a brick wall…

Answer 17

The kinetic energy store would transfer to a thermal energy store

Question 18

Two points about kinetic energy:

Answer 18

• It is the energy result of its speed.

- Energy an object has when it’s moving

Question 19

What is the equation for kinetic energy?

Answer 19

Kinetic energy = 1/2 x mass x speed²

KE = 1/2 x m x v²

Question 20

Two points about gravitational potential energy:

Answer 20

• it is the energy it has due to its height in a gravitational field.
• if an object is lifted up it will gain GPE

Question 21

What is the equation for gravitational potential energy?

Answer 21

Gravitational potential energy = mass x gravitational field strength x height

GPE = m x g(gfs) x h

Question 22

Two points about elastic potential energy:

Answer 22

• When is spring is stretched or compressed work is done on the spring which will result in a transfer of energy to the spring’s elastic store.
• The work done on the spring is equal to the amount of energy stored.

Question 23

What is the equation for elastic potential energy?

Answer 23

Energy = 0.5 x spring constant x extension²

E = 1/2 k x²

Question 24

‘A gas cooker, heating a pan of water, takes energy from the ______store of the gas and transfers it to the ______ store of the water’
Fill in the blanks:

Answer 24

1. Chemical

2. Thermal

Question 25

What forms of energy have a tendency to spread out (dissipate)?

Answer 25

Heat, light and sound energy

Question 26

What three disadvantages are there to dissipation of energy?

Answer 26

• becomes very difficult to gather the energy back together again.
• results in energy becoming less useful
• whenever a process produces unwanted heat, light or sound Energy that ends up in those forms is essentially wasted.

Question 27

In which two ways can energy loss be reduced?

Answer 27

• Reducing the amount of unwonted energy that is produced.

- Preventing energy from dissipating.

Question 28

How can you prevent wanted heat from dissipating less heat?

Answer 28

Insulators:

• how will the installation conduct heat
• How thick the installation is

Question 29

What usually happens whenever energy transferred from one form to another? And what energy forms does it usually turn in to?

Answer 29

Some of that energy is usually wasted and ends up in the form of heat, light or sound.

Question 30

What is the efficiency of a system?

Answer 30

The proportion of energy that ends up in the intended form.

Question 31

What is the equation for efficiency?

Answer 31

Useful energy transferred by device
Efficiency = ————————————————————
Total energy supplied to the device

Question 32

What number is efficiency usually given as?

Answer 32

A number between 0 to 1 but it can occasionally be given as a percentage.
For example 40% of efficiency is the same as the efficiency of 0.4 and 1 efficiency is the same as 100% efficient.