Forces- P5 - Paper 2

Question 1

Vectors

Answer 1

Magnitude + direction
-force, velocity, displacement, acceleration, momentum

Question 2

Scalar

Answer 2

Only magnitude and no direction
Distance

Question 3

What is a contact force? (Name 4)

Answer 3

When 2 objects have to be touching for a force to act.
Friction, air resistance, tension in ropes, normal contact force.

Question 4

What is mass? (2 points)

Answer 4

The amount of ‘stuff’ in an object. Every objects mass is the same everywhere in the universe

Question 5

What is weight? (2 marks)

Answer 5

The force acting on an object due to gravity. Weight of an object depends on the strength on the gravitational field strength.

Question 6

What is the equation for weight? (With units)

Answer 6

Weight (N) = Mass (kg) x Gravitational Field Strength (N/kg)

Question 7

Which of these are vector and which are scalar:
-force
-speed
-distance
-velocity
-displacement

Answer 7

Vectors:
-force
-velocity
-displacement

Scalar:
-speed
-distance

Question 8

3 contact forces:

Answer 8

Friction
Air resistance
Tension

Question 9

3 non-contact forces:

Answer 9

Magnetic
Gravitational
Electrostatic

Question 10

What can you use to measure an objects weight?

Answer 10

A newton meter

Question 11

What is the equation that can be used to determine an objects weight?

Answer 11

Weight (N)= mass (kg) x Gravitational field strength (N/kg)

Question 12

Calculate the weight of an object on the moon if its mass is 3kg. The gravitational field strength of the moon is 1.6N/kg.

Answer 12

W=MxGFS
W=3x1.6
W=4.8

Question 13

Calculate the weight of an object on the moon if its mass is 3kg. The gravitational field strength of the moon is 1.6N/kg.

Answer 13

W=MxGFS
W=3x1.6
W=4.8

Question 14

What is the effect on an object’s weight if its mass was doubled?

Answer 14

The weight is also doubled.

Question 15

1000N
^
^
600N < van&raquo_space; 800N
v
v
1000N
Calculate the resultant forces acting on the van above: horizontal and vertical.

Answer 15

Horizontal force: 200N to the right
Vertical force: Equilibrium/ 0N

Question 16

1000N
^
^
600N < van&raquo_space; 800N
v
v
1000N
On the diagram, what 2 things do the arrows show?

Answer 16

1. Direction of force
2. Relative size

Question 17

Complete the sentences below:

Elastic deformation occurs when a force has been applied to a spring and it …………….. to its original shape. …………. …………….. occurs when the spring does not return to its original shape.

Answer 17

1. Returns
2. Inelastic deformation

Question 18

State the equation that links force, spring constant and extension.

Answer 18

Force = spring constant x extension

Question 19

Define work done.

Answer 19

This occurs when a force moves an object for a distance.

Question 20

State the equation that links work done, force and distance.

Answer 20

Work done= force x distance

Question 21

Units for work done, force, distance.

Answer 21

Work done, Joules (J)
Force, Newtons (N)
Distance, meters (M)

Question 22

A lorry travels 200m when the brakes are applied with a force of 600N. Calculate the work done to stop the lorry.

Answer 22

Wd= fxd
Wd=600x200
Wd=120,000J

Question 23

State 3 factors that could affect a person’s walking speed.

Answer 23

1. Age
2. Fitness
3. Terrain

Question 24

A car increases its velocity from 5m/s to 12m/s in a time of 10 seconds. Calculate its acceleration. (Units)

Answer 24

Acceleration= change in velocity/time
A=(12-5)/10
A=7/10
A=0.7m/s2

Question 25

Explain the term deceleration.

Answer 25

Negative acceleration, the speed going down.

Question 26

What is the calculation for stopping distance.

Answer 26

Stopping distance= thinking distance + breaking distance

Question 27

What affects thinking distance?

Answer 27

Speed Tiredness Reaction time Drugs Alcohol Distractions

Question 28

What affects braking distance?

Answer 28

Tyres Road conditions Brake conditions

Question 29

Let the mass of a car be 1500kg. One car is travelling at a speed of 20m/s and a second car is travelling at 15m/s. Calculate the force exerted if they were to hit an object.

Answer 29

Force = mass x acceleration Car 1 1500 x 20 30,000N Car2 1500 x 15 22,500N

Question 30

Describe the effect of friction on a moving object.

Answer 30

It slows it down

Question 31

State 2 ways friction can be overcome.

Answer 31

- using lubricant - smoother surface

Question 32

What is terminal velocity?

Answer 32

When an object is falling at a steady speed. Frictional force is equal to acceleration force so reaches maximum speed.

Question 33

Terminal velocity depends on 2 things:

Answer 33

Shape Area

Question 34

Explain the term conservation of momentum.

Answer 34

The total momentum before an event is the same as after the event.

Question 35

State the equation and the units to calculate momentum.

Answer 35

Momentum (kg m/s) = mass (kg) x velocity (m/s)

Question 36

A car has a mass of 1500kg and a momentum of 7500kgm/s. Calculate its velocity.

Answer 36

Velocity = momentum/ mass V= 7500/ 1500 V= 5m/s

Question 37

State the equation that links force, mass and acceleration.

Answer 37

Force= mass x acceleration

Question 38

Calculate the force acting on an object with a mass of 15kg and acceleration of 4m/s2.

Answer 38

F=mxa F= 15 x 4 F= 60N

Question 39

When an object moves in a circular motion, explain what happens to its direction and velocity if its speed remains constant.

Answer 39

Its direction and velocity will be constantly changing.