Question 2.1.4: Additional Answer Options

2.1.1

F	FA / 90N / F90
w	Fg / Fw / weight/mg / Gravitational force
f	(Kinetic) Friction / Ff / / fk
N	FNormal / Normal / FN

Tips:

• As of 2024 no marks will be awarded for free-body diagrams if the weight has been resolved into two components.
• Since the question is out of four marks, it indicates that four forces are acting on the lawn mower.

4 marks

(4 x 1 mark)

2.1.2

It is moving at constant speed in a straight line, the acceleration is zero/ the net force (resultant) acting on it is zero/it is moving at constant velocity.

Tips:

• When an object is in equilibrium, there is no resultant force acting on the system so the object moves at a constant velocity or remains at rest.
• In this case, the person is pushing the lawnmower at a constant speed so it must be in equilibrium.

1 mark

2.1.3

Option 1

Any one ⁽¹⁾

⁽²⁾

⁽³⁾

Or

Option 2

Any one ⁽¹⁾

⁽²⁾

⁽³⁾

Or

Option 3

Any one ⁽¹⁾

⁽²⁾

⁽³⁾

  Tip: the horizontal component of the applied force must be equal to the friction for the lawnmower to move at a constant speed.

3 marks

(3 x 1 mark)

Marking criteria:

• ⁽¹⁾ Formula
• ⁽²⁾ Substitution
• ⁽³⁾ Answer

2.1.4

How to approach this question:

• You need to calculate the acceleration using the given information.

Option 1

Part 1:

Part 2:

• Use Newton's second law to calculate the force.

• Remember, you are asked for the force and not just the horizontal component of the force.

Or

There are more ways to answer this question. To view other options, click here.

6 marks

(6 x 1 mark)

2.2

Option 1

Or

Option 2

Tip: the universal gravitational constant, G, is given on the formula sheet.

4 marks

(4 x 1 mark)