There is a curious anomaly around today. When we discuss our weight we invariably refer to the number of kilograms we ‘weigh’. But this is a measurement of mass, not weight! So, if someone claim a weight of 100 kg, they are really referring to their mass.
This is where it gets interesting. To find the actual wight we need to multiply the mass with the gravitational acceleration on whichever planet you happen to be on.
So, on the Earth, where g = 9.8 m/s^2, a 100 kg person will weigh 980 Newtons (since it was Newton who devised the famous ‘F = ma’ law originally).
But, on Mars, with its significantly lower gravitation acceleration, that person would weigh only 37.7 kg. (On Earth’s moon it would be only 16.6 kg while on Jupiter it would be 252.8 kg!!)
Whatever you do, don’t go to a white dwarf star – there a 100 kg would weigh 130 million kg!!! Crushing….
So the next time someone criticises your weight, just tell them you’re on the wrong planet!
Why we discuss our weight in terms of mass is a mystery to me. If anyone knows, please tell me. In the meantime, where’s that cream bun……?
Mike.
Go to https://www.exploratorium.edu/ronh/weight/ for a bit of fun.
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