4.5 Forces

Question 1

What is Newton’s First Law of Motion?

Answer 1

An object remains at rest or continues to move at a constant velocity unless acted upon by a resultant external force.

Question 2

What is Newton’s Second Law of Motion?

Answer 2

The acceleration of an object is directly proportional to the resultant force acting upon it and inversely proportional to its mass, expressed as F = m × a.

Question 3

What is Newton’s Third Law of Motion?

Answer 3

For every action, there is an equal and opposite reaction; forces always occur in pairs acting on two interacting objects.

Question 4

What is inertia?

Answer 4

The tendency of an object to resist changes in its state of motion; objects with greater mass have greater inertia.

Question 5

What is momentum?

Answer 5

The product of an object’s mass and velocity, given by the equation: momentum (p) = mass (m) × velocity (v).

Question 6

What is the principle of conservation of momentum?

Answer 6

In a closed system, the total momentum before an event is equal to the total momentum after the event, provided no external forces act.

Question 7

What is terminal velocity?

Answer 7

The constant maximum velocity reached by a falling object when the force of air resistance equals the weight of the object, resulting in zero acceleration.

Question 8

What factors affect braking distance?

Answer 8

Braking distance is affected by the speed of the vehicle, the condition of the brakes and tyres, and the road surface.

Question 9

What factors affect thinking distance?

Answer 9

Thinking distance is influenced by the driver’s reaction time, which can be affected by factors such as fatigue, alcohol, drugs, and distractions.