He could be walking in space in ‘microgravity’……
He could be walking on the Moon….
He could be walking on Mars…
He could be walking on the surface of the dwarf planet Pluto…
He could be trying to walk on the surface of the gas giant Jupiter…..( although this would be impossible since he would quickly sink into a sea of liquid hydrogen)
No matter where he is, his mass will always remain constant (stay the same) The amount of ‘stuff’ inside him does not change!
So if his mass always stays the same, what about his weight?
On Earth he weighs 12 stone 1lb (77.1kgs)
In ‘microgravity’ he would weigh 10 stone 12lbs (69.4 kgs)
On the moon he would weigh 2 stones (12.7 kgs )
On Mars he would weigh 4 stone 7lbs (29 kgs)
On the dwarf planet Pluto he would weigh 0 stone 11lbs (4.9 kgs)
On the ‘surface’ of the gas giant Jupiter he would weigh an amazing 28 stone 9lbs! (182.3 kgs)
Let’s see what Homer Simpson thinks!
Homer Simpson weighs himself on a set of bathroom scales. He doesn’t look very happy!
He weighs 21 stones! (133.8 kgs)
Homer may believe he is measuring how heavy he is but what he is actually measuring is the force of gravitational attraction between himself and the Earth.
The force of gravitational attraction between Homer Simpson and the Earth just so happens to be called ‘weight’.
We usually measure the force of gravitational attraction in stones or kilograms.
Homer knows that he has eaten too many burgers and hot dogs. He wants to lose weight and lose it FAST!
He thinks carefully about what to do!
He comes up with a cunning plan!
He knows he could lose weight if he leaves planet Earth…..
If he ‘floats’ in orbit 250 miles above the surface of the Earth where the force of gravity is 90% of what it is on the surface of the Earth he would weigh 19 stones (120.4 kilos) He would have lost 2 stones in weight!
If he walks on the Moon, where the force of gravitational attraction is 20% of what it is on Earth, he would weigh 3 stone 8lbs. (22.6 kilos)
If he walks on Mars, where the force of gravitational attraction is 38% of what it is on Earth, he would weigh 7 stone 12 lbs. (50.4 kilos)
If he walks on the dwarf planet Pluto, where the force of gravitational attraction is 8% of what it is on Earth, he would weigh 1 stone 5 lbs. (8.9 kilos)
On the ‘surface’ of the gas giant Jupiter, where the force of gravitational attraction is 254% of what it is on Earth, he would weigh an incredible 49 stone 11 lbs! (316.3 kilos) He would, however, immediately sink into a sea of liquid hydrogen!
So what is the force that could make Homer Simpson’s weight change depending on which planet he is on?
It’s called G-R-A-V-I-T-Y!
Homer decides that it is not a good idea to lose weight by becoming an astronaut and visiting other planets which have lesser forces of gravitational attraction!
He thinks that the best way to lose weight would be to stay on Earth and stop eating so much!