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 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 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. Teacher notes: Talk about man on the moon – did he walk normally? (No) It was the gravity that made him so light. Why didn’t the space rocket ‘fly’ off too? (It’s mass was much greater than a man!) Going to the moon is one sure way to lose weight! You might want to go further and talk about walking on Jupiter (has a much greater mass) and gravitational pull is stronger, so walking would be impossible. We would be much heavier on Jupiter! We might look very different if our planet’s mass was much greater – we would have had to evolve to cope with a much stronger gravitational pull.. maybe we’d be short and squat!

Gravity – what is it? Which arrow is pointing the wrong way? Teacher notes: Talk about man on the moon – did he walk normally? (No) It was the gravity that made him so light. Why didn’t the space rocket ‘fly’ off too? (It’s mass was much greater than a man!) Going to the moon is one sure way to lose weight! You might want to go further and talk about walking on Jupiter (has a much greater mass) and gravitational pull is stronger, so walking would be impossible. We would be much heavier on Jupiter! We might look very different if our planet’s mass was much greater – we would have had to evolve to cope with a much stronger gravitational pull.. maybe we’d be short and squat!

Gravity – what is it? Yes, it’s this one Teacher notes: Talk about man on the moon – did he walk normally? (No) It was the gravity that made him so light. Why didn’t the space rocket ‘fly’ off too? (It’s mass was much greater than a man!) Going to the moon is one sure way to lose weight! You might want to go further and talk about walking on Jupiter (has a much greater mass) and gravitational pull is stronger, so walking would be impossible. We would be much heavier on Jupiter! We might look very different if our planet’s mass was much greater – we would have had to evolve to cope with a much stronger gravitational pull.. maybe we’d be short and squat! 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)

Weight = Mass x Gravity

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

WEIGHT = MASS x GRAVITY (N) (kg) (N/kg) So GRAVITY on Earth is said to be 10 N/kg WEIGHT = MASS x GRAVITY (N) (kg) (N/kg)

The astronaut has a mass of 80kg but when will he weigh more? on the Moon on the Earth Gravity = 10 N/kg Gravity = 1.5 N/kg Weight = 80 x 1.5 Weight = Weight = 80 x 10 Weight = 120 N 800 N