Topic 8

Question 1

Work done =

Answer 1

Force x distance moved in diraveyuon of force

J. N. M

Question 2

Power =

Answer 2

Works done / time taken

J. S

Question 3

The energy of a system can be changed by

Answer 3

Work done through forces
- a body can be lifted through a vertical height by a force. This will increase the store of GPE

Electrical equipment
- a cell in a circuit provides a potential difference so that components in the circuit can transfer energy into other forms such as thermal

Heating a material
- supplying thermal energy to a system will increase the Ke of the particles in the material. It’s temperature will increase if it is not changing state.

Question 4

Pairs of forces can interact at

Answer 4

A distance or by direct contact

Question 5

Forces can be exerted between objects without them being in comtact with one another. There are three non-contact forces you need to know about

Answer 5

Gravity
Magnetism
Electrostatic charges

Question 6

Gravity

Answer 6

Acts between allxnasses. It’s always attractive

Question 7

Magnetism

Answer 7

Acts between magnetic poles unlike poles attract and like poles repel

Question 8

Electrostatic charges

Answer 8

Exert forces on each other at a distance unlike charges attract and like charges repel

Question 9

Forces can be exerted between objects due to them being

Answer 9

In contact

Question 10

The normal contact force acts

Answer 10

Upwards in opposition to the weight of the object

The interaction pair is the force of the ground on the box and the force of the box on the ground

Question 11

An archer fires an arrow from a bow. Describe the contact and non-contact forces involved in firing the arrow

Answer 11

Contact forces include the normal force acting on the arrow
Friction as it moves through the air and the tension in the string
Non contact forces include gravity once it has been released

Question 12

A resultant force can be resolved into its

Answer 12

Horizontal and vertical component forces

Question 13

What do free body diagrams show

Answer 13

The forces acting on a single object

Question 14

Free body diagrams contain

Answer 14

The body the forces are acting on - this can be simplified to a box or a dot

The forces acting on the body
- this will depend on the complexity of the problem and the assumptions being made

Question 15

Resultant forces determine wether a body will be

Answer 15

Stationary
Moving at constant speed
Accelerating

Question 16

What is a moment

Answer 16

When Forces act at a distance from a pivot cause a turning effect or roatation

Question 17

Moment =

Answer 17

Force x distance normal to the direction of the force

Nm. N. M

Question 18

The distance must be measure from the pivot normal to the direction of the force. The pivot is the

Answer 18

Point about which the object rotates

Question 19

What is the principle of moments

Answer 19

Sum of clockwise moments = sum of anti-clockwise moments

For riatational forced in an equilibrium

Question 20

A lever can cause a rotation which depends on the position of

Answer 20

The input force
The output force
The fulcrum

Question 21

Gears are

Answer 21

Toothed wheels that are meshed together to transmit rotational force and motion.

Each gear in a series reversed the direction of motion

A larger fear will roatate more slowly than a smaller gear but will have a greater training eggevt
A low gear leads to a low speed and a high turning effect

Question 22

A Hugh gear is when

Answer 22

A large input gear turns s smaller output gear

High speed
Low turning effect

Question 23

A low gear

Answer 23

is when s smaller input gear turns s larger gear

Low speed
Hugh turning effect

Question 24

Describe he common features of gears and levers in terms of how they work

Answer 24

Gear and levers both transmit the rotational effect of a force and they can alter the size of the output force compared with the input force

Question 25

Look at component symbols

Answer 25

Make actual Flashcards

Question 26

Series circuits

Answer 26

Contains just one loop which an electric current can flown

Question 27

Characteristics of series circuits

Answer 27

Electrons do not flow through any of voltmeters
Ammeters are always connected in series with components
The size of the current in a series circuit is the same at every point in the circuit. All three ammeters in this circuit will show the same value for current
Voltmeters have a very high resistance so that no current will flow through them
The pd accord components that are arranged in series must add up to give the cell voltage

Question 28

Parallel circuits

Answer 28

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