Section 1 - Forces and Motion

Question 1

Units for speed and velocity

Answer 1

m/s

Question 2

Difference between speed and velocity

Answer 2

Speed is a scalar quantity, velocity is a vector quantity

Question 3

Formula for speed

Answer 3

s = d/t

Question 4

Formula for acceleration

Answer 4

a = Δv/Δt

Question 5

Gradient in distance-time graphs

Answer 5

Speed

Question 6

Flat sections in distance-time graphs

Answer 6

Object has stopped

Question 7

Negative gradient in distance-time graphs

Answer 7

Object is going towards starting point

Question 8

Curves in distance-time graphs

Answer 8

Acceleration/Deceleration

Question 9

Gradient in velocity-time graphs

Answer 9

Acceleration

Question 10

Flat sections in velocity-time graphs

Answer 10

Constant speed

Question 11

Area under a velocity-time graph

Answer 11

Distance travelled

Question 12

Curves in velocity-time graphs

Answer 12

Change in acceleration

Question 13

Gravity on Earth

Answer 13

g = 10 m/s²

Question 14

Formula for weight

Answer 14

W = m*g

Question 15

How to measure weight

Answer 15

Using a spring balance or a newton meter

Question 16

Unit for mass

Answer 16

kg

Question 17

Unit for weight

Answer 17

N

Question 18

7 types of force

Answer 18

Weight, reaction force, electrostatic force, thrust, drag, lift, tension

Question 19

Two types of friction

Answer 19

Static friction and sliding friction

Question 20

First law of motion

Answer 20

Balanced forces mean no change in velocity

Question 21

Second law of motion

Answer 21

A resultant force means acceleration

Question 22

Third law of motion

Answer 22

Reaction forces

Question 23

Equation for force

Answer 23

F = m*a

Question 24

Vectors have…

Answer 24

magnitude and direction

Question 25

Scalars have…

Answer 25

magnitude

Question 26

Factors affecting stopping distance

Answer 26

Thinking distance, braking distance

Question 27

Factors affecting thinking distance

Answer 27

Speed, internal influences(drugs/old age)

Question 28

Factors affecting braking distance

Answer 28

Speed, mass of vehicle, condition of brakes, road surface, weather condition, tyre condition

Question 29

Formula for momentum

Answer 29

p = m*V

Question 30

Unit for momentum

Answer 30

kgm/s

Question 31

Conservation of momentum

Answer 31

Momentum before = Momentum after

Question 32

Formula for force in terms of momentum and time

Answer 32

F = Δp / Δt

Question 33

Definition of a moment

Answer 33

The turning effect of a force

Question 34

Formula for a moment(Nm)

Answer 34

Force(N) * perpendicular distance between line of action and pivot(m)

Question 35

The centre of gravity hangs

Answer 35

Directly below the point of suspension

Question 36

When an object is balanced

Answer 36

Total anti-clockwise moments = Total clockwise moments

Question 37

Forces across supports

Answer 37

• Are not equal
• If a heavy object is placed, the supports closest to the object will provide a larger force
• The weight is balanced by the tension forces in the cables
• Look at page 13

Question 38

Hooke’s law

Answer 38

Extension is proportional to force: this is represented as a straight line on a graph

Question 39

When does Hooke’s law stop working?

Answer 39

When the force becomes greater than the elastic limit; permanently stretching the material

Question 40

Elastic behaviour

Answer 40

• A material displays elastic behaviour if it returns to its original shape once the forces are removed
• Metals display an elastic behaviour as long as Hooke’s law is obeyed

Question 41

What is an orbit?

Answer 41

An orbit is a balance between the forward motion of the object and a force pulling it inwards