Unit 2 - Resultant Forces

Question 1

Name the force allowing a cyclist to move forwards.

Answer 1

Friction (between the road and the tyres)

Question 2

Which force increases as an objects speed increases?

Answer 2

Air resistance.

Question 3

Give the unit for weight.

Answer 3

Newtons, all forces are measured in Newtons (N)

Question 4

What is the size of a resultant force acting on an object travelling at a steady speed?

Answer 4

Zero.

Question 5

Give the unit for acceleration.

Answer 5

m/s2

Question 6

Define resultant force.

Answer 6

The overall force acting on an object.

Question 7

What is velocity?

Answer 7

The speed of an object in a given direction.

Question 8

Give the weight of an object with a mass of 90Kg. Force = mass x gravity (gravity = 10)

Answer 8

900N. 10 x 90.

Question 9

Describe the motion of an object moving forward if there is a resultant force acting on it in the other direction.

Answer 9

It will be slowing down.

Question 10

Why does a skydiver slow down when they open a parachute?

Answer 10

The parachute has a large surface area and so the air resistance increases to give a resultant force upwards.