Topic 5a- Forces

Question 1

What is the resultant force?

Answer 1

The net force acting upon an object.

Question 2

What is Newton’s first law of motion?

Answer 2

An object remains stationary or moves at a constant velocity unless being acted upon by an external resultant force.

Question 3

What is Newton’s second law of motion?

Answer 3

The resultant force = mass x acceleration

Question 4

What is Newton’s third law of motion?

Answer 4

If object A exerts a force on object B, object B exerts an equal and opposite force on object A.

Question 5

What is the equation for stopping distance?

Answer 5

Thinking distance + braking distance

Question 6

What are vector quantities?

Answer 6

Quantities that have both magnitude and direction

Question 7

What are scalar quantities?

Answer 7

Quantities that have magnitude but no direction

Question 8

Give examples of contact forces

Answer 8

• friction
• air resistance
• tension
• upthrust
• normal contact

Question 9

Give examples of non-contact forces

Answer 9

• magnetic force
• electrostatic forces
• gravitational forces

Question 10

What are the two important effects of gravity?

Answer 10

1. On the surface of a planet, it makes all things accelerate towards the ground
2. It gives everything a weight

Question 11

What unit is weight measured in?

Answer 11

Newtons

Question 12

What is the gravitational field strength on Earth?

Answer 12

~9.8N/kg

Question 13

What is the gravitational field strength on the moon?

Answer 13

1.6N/kg

Question 14

What does it mean if an object is at equilibrium?

Answer 14

The resultant force acting upon it is 0N

Question 15

What is work done?

Answer 15

Work done is the energy transferred when a force moves an object through a distance

Question 16

What are work done and energy transferred given in?

Answer 16

Joules