The SI unit for force is

**Newton (N)**. It is a

*vector quantity*.

Force is a push or a pull. Force is therefore that which changes a body’s state of motion or shape.

The SI unit for force is**Newton (N)**. It is a *vector quantity*.

The SI unit for force is

- Earth's gravitational force is the force which pulls a body towards its center. This pull of gravity is called

a)

b)

The SI unit for mass is the

Weight = Mass x g, where g is the

It is the quantity of matter in a body

It is measured in kilograms

It is the same everywhere

It is measured using a beam balance

Has magnitude only Weight

It is the pull of gravity on a body

It is measured in newton's

It changes from place to place

Measured using a spring balance

Has both magnitude and direction

-- select another example --

The length of a spring is 16.0 cm. its length becomes 20.0 cm when supporting a weight of 5.0 N.
Calculate the length of the spring when supporting a weight of 6.0 N.

*Solution*

5N stretches to a length of (20.0 - 16.0) = 4cm

hence 1N = 4 ÷ 5 = 0.8 cm

Therefore, 6.0 x 0.8 = 4.8cm

Overall length will be: 16.0 + 4.8 = 20.8cm

**= 20.8**

5N stretches to a length of (20.0 - 16.0) = 4cm

hence 1N = 4 ÷ 5 = 0.8 cm

Therefore, 6.0 x 0.8 = 4.8cm

Overall length will be: 16.0 + 4.8 = 20.8cm

A **scalar quantity** is a quantity which has magnitude (size) only . Examples are distance, mass, speed

A**vector quantity** is a quantity which has both magnitude and direction. Examples are displacement, weight, velocity

A