GUESS THE WEIGHT OF THE CHOCOLATE BAR REMEMBER

GUESS THE WEIGHT OF THE CHOCOLATE BAR REMEMBER TO INCLUDE UNIT OF MEASUREMENT

Answer • 1. 5 N but why?

• Mass is a measure of how much matter or particles an object has. It has the units kg or grams. • Weight is a measure of how strongly gravity pulls on that matter. It has the units Newton’s (N). • So if you were to travel to the moon, where gravity is weaker, what would change?

• I have two bags, both the same shape and size. One bag contains feathers and the other contains bricks. Which is heavier? . . • Which is heavier a ton of bricks or a ton of feathers? . .

Gravity – what is it? • An attractional force between objects with mass. • Gravity acts on the Earth by pulling objects towards its centre. • An object with heavier mass has a stronger gravitational pull = has a larger weight.

Gravity – what is it? Which arrow is pointing the wrong way?

Gravity – what is it? Yes, it’s this one

How do we measure it? • We measure all forces in Newton’s. The effect of gravity gives us our weight - so our weight should always be in Newton’s. Newtonmeter (also called Forcemeter, Spring balance, and Pullmeter)

Gravity on Earth causes this man to accelerate downwards. Its effect is the same everywhere.

WEIGHT = MASS x GRAVITY (N) (kg) (N/kg)

The astronaut has a mass of 80 kg but when will he weigh more? on the Moon Gravity = 1. 5 N/kg Weight = 80 x 1. 5 Weight = 120 N on the Earth Gravity = 10 N/kg Weight = 80 x 10 Weight = 800 N