Unit 9B - Recall Questions - Forces and Motion

Question 1

Name the 3 non-contact force fields.

Answer 1

Gravitational, electrostatic and magnetic fields

Question 2

Name 4 common contact forces.

Answer 2

Contact force, friction, air resistance & tension

Question 3

Which contact force occurs between two moving surfaces?

Answer 3

Friction

Question 4

What does the length of a force arrow represent?

Answer 4

Size of the force

Question 5

What is a resultant force?

Answer 5

The sum of two forces acting in opposite directions

Question 6

What can we say about a resultant force that is zero?

Answer 6

The forces are balanced

Question 7

What is the gravitational field strength (g) on Earth?

Answer 7

10 N/kg

Question 8

What is the acceleration due to gravity (g) near the Earth’s surface?

Answer 8

10 m/s2

Question 9

What are the units for force?

Answer 9

N (newtons)

Question 10

What are the units for weight?

Answer 10

N (newtons)

Question 11

What are the units for mass?

Answer 11

kg (kilograms)

Question 12

Which equipment is used to measure weight?

Answer 12

force meter / newton meter

Question 13

What is the symbol for proportionality?

Answer 13

∝

Question 14

What is the equation for Newton’s second law of motion?

Answer 14

F∝ m x a

Question 15

Why does an object at constant speed in circular motion have a constantly changing velocity?

Answer 15

Because the direction is constantly changing

Question 16

In which direction does the centripetal force act?

Answer 16

Towards the centre of the circle