Topic 1: Key Concepts in Physics

Question 1

Define a scalar quantity and give two examples.

Answer 1

A scalar quantity has magnitude only. Examples:
* Speed
* Distance

Question 2

Define a vector quantity and give two examples.

Answer 2

A vector quantity has magnitude and direction. Examples:
* Velocity
* Force

Question 3

What is the SI unit for energy?

Answer 3

Joule (J)

Question 4

What is the formula for calculating weight?

Answer 4

Weight = Mass × Gravitational field strength (W = mg)

Question 5

What is the value of gravitational field strength on Earth?

Answer 5

9.8 N/kg

Question 6

What is the difference between mass and weight?

Answer 6

Mass is the amount of matter (kg), while weight is the force due to gravity (N)

Question 7

How do you calculate work done?

Answer 7

Work done = Force × Distance (W = Fd)

Question 8

What is the principle of moments?

Answer 8

For an object in equilibrium, the sum of clockwise moments equals the sum of anticlockwise moments

Question 9

What is Hooke’s Law?

Answer 9

Force = Spring constant × Extension (F = kx)

Question 10

What is the unit of power?

Answer 10

Watt (W)