Forces GCSE

Question 1

Scalar Quantities

Answer 1

Quantities with magnitude only

Question 2

Vector Quantities

Answer 2

Quantities with magnitude and direction

Can be represented with an arrow

Question 3

Force

Answer 3

A push or a pull acting on an object due to the interaction with another object

Question 4

Types of forces

Answer 4

Contact and non-contact

Question 5

Examples of contact forces

Answer 5

• Friction
• Air resistance
• Tension
• Normal contact force

Question 6

Examples of non-contact forces

Answer 6

• Gravity
• Magnetic force
• Electrostatic force

Question 7

Examples of scalar quantities

Answer 7

• Mass
• Time
• Distance
• Speed

Question 8

Examples of vector quantites

Answer 8

• Velocity
• Weight
• Force
• Displacement

Question 9

Weight Formula

Answer 9

W = MG

Weight = Mass x Gravitational field strength

Question 10

What is the relationship between weight and mass?

Answer 10

Directly proportional

Question 11

How is weight measured?

Answer 11

Newton meter

Question 12

Resultant force

Answer 12

The single force which has the same effect as all of the forces acting on it

Question 13

Work done

Answer 13

When a force causes an object to move through a distance

Question 14

Work done formula

Answer 14

WD = FD

Work done = Force x Distance

Question 15

Elastic deformation

Answer 15

If an elastic object is stretched, bent or compressed, it returns to its original shape once the forces are removed

Question 16

Inelastic deformation

Answer 16

When an object does not return to its original form after being bent, compressed or stretched

Question 17

Hooke’s Law

Answer 17

F = ke

Extension of an elastic object is directly proportional to the force applied to it, providing the limit of proportionality is not exceeded

Question 18

Elastic potential energy formula

Answer 18

Ep = 1/2ke^2

Question 19

What is a moment

Answer 19

The turning effect of a force

Question 20

Moment formula

Answer 20

M = FD
Moment = Force x Distance

Question 21

What happens when an object is balanced?

Answer 21

The total clockwise movement about a pivot is equal to the total anticlockwise movement

Question 22

What do levers and gears do?

Answer 22

Act as a force multiplier by the use of moments.

Make moving heavy objects easier because less effort can be put in but for a greater force output

Question 23

What is a fluid (pressure?

Answer 23

Liquid or gas

Question 24

How does pressure exert forces in a fluid?

Answer 24

Pressure exerts force at right angles to any surface

Question 25

Pressure formula (1)

Answer 25

P = F / A

Question 26

Pressure formula (2)

Answer 26

P = hpg Pressure = Height of column x density of water x gravitational field strength Pascals, meters, kg/m^3, N/kg

Question 27

What is upthrust?

Answer 27

The resultant force upwards due to greater pressures on the bottom an object

Question 28

Displacement

Answer 28

The distance an object moves in a straight live from the start point to the end point

Question 29

Speed of sound in air

Answer 29

330 m/s

Question 30

Distance formula

Answer 30

Distance = Speed / Time

Question 31

Velocity

Answer 31

Speed associated with a given direction.

Question 32

Distance/Time Graph

Answer 32

Used if an object moves along a straight line.

Question 33

Gradient of a Distance/Time Graph at time t.

Answer 33

Speed at time t.

Question 34

Acceleration

Answer 34

The rate at which speed changes over time

Question 35

Formula for acceleration

Answer 35

(v-u)/t - Change in Velocity over time

Question 36

Gradient of a Velocity/Time Graph at time t.

Answer 36

Acceleration at time t

Question 37

Area under a Velocity/Time graph represents...

Answer 37

The displacement of the object.

Question 38

Equation for uniform acceleration

Answer 38

v^2-u^2=2as

Question 39

Newtons first law

Answer 39

If a body is at rest or moving at constant speed in a straight line, it will remain at rest or in motion at constant speed until acting upon by a force

Question 40

Inertia

Answer 40

The tendency of an object to continue in their state of rest or uniform motion

Question 41

Newtons second law

Answer 41

F = ma Force directly proportional to the acceleration of an object

Question 42

Inertial mass

Answer 42

A measure of how difficult it is to change the velocity of an object

Question 43

Newtons third law

Answer 43

Whenever 2 objects interact, they exert equal and opposite forces on each other. The two forces must act on the two different objects and the force must be of the same type

Question 44

Stopping distance

Answer 44

Distance an object travels, calculated by the sum of the braking distance and the thinking The greater the speed, the greater the stopping distance

Question 45

What factors can influence reaction time

Answer 45

- Tiredness - Drugs - Alcohol - Distractions

Question 46

What methods are used to measure reaction time?

Answer 46

- Ruler drop test

Question 47

Factors affecting braking distance

Answer 47

- Rain - Ice -

Question 48

Factors affecting braking distance

Answer 48

- Rain - Ice - The greater the speed, the greater the braking distance because more braking force is required - The greater the braking force, the greater the deceleration of the vehicle so the stopping distance is decreased

Question 49

What affects braking distance (forces)

Answer 49

When a force is applied to the brakes of a vehicle, work is done by the friction force between the brakes and the ground, so the wheel reduced kinetic energy of the vehicle and the temperature of the brakes increases

Question 50

What are the dangers of large decelerations

Answer 50

- Tires may overheat due to friction between the tyre and the road - Causing it to wear out - So less grip for rainy or icy conditions - Which could cause future accidents - Loss of control, skidding

Question 51

Momentum formula

Answer 51

P = MV

Question 52

What is the total momentum change after a collision between two or more objects in a closed system?

Answer 52

No change - total momentum after an event is equal to the total momentum before an event

Question 53

When does a change in momentum occur?

Answer 53

When a force acts on an object that is moving

Question 54

What is an equation for momentum involving force?

Answer 54

F = mΔv / t

Question 55

What are some safety features to reduce momentum of impact?

Answer 55

- Seatbelts - Air bags - Cushioned playground surfaces - Cycle helmets - Crash mats

Question 56

How do safety features reduce the momentum of an impact?

Answer 56

- Increases time taken for impact to stop during a collision - So stopping time increases - Which decreases acceleration - So force decreases (f = ma) - So rate of change of momentum decreases