Why is the mass of a bowling ball the same on earth and on the moon but the weight of the bowling ball on earth different on the moon?

Answer 1

You need to understand that MASS is an intrinsic property of matter, the Bowling ball will have the same mass no matter where it is.

WEIGHT is the pull of gravity on matter. As gravity is weaker/less on the Moon as compared to Earth, the same size lump of matter (the bowling ball) will weigh less on the Moon as it does on Earth.

The problem in understanding this difference happens because as we live on Earth we confused MASS and WEIGHT before we understood the physics. On Earth a 1 Kg mass weighs 1 Kg, however if we take that 1 kg mass to the Moon where gravity is only one third of that on Earth it will only weigh 1/3 Kg.

However, there is another property of matter that is related directly to its Mass and that is the energy you need to put in to get it to move (or stop moving) - this is called INERTIA.

Weather on the Moon or on the Earth the INERTIA of the bowling ball will remain the same. If you roll it to another person on a horizontal surface on the Moon or on Earth, the person you roll it to will find it just as hard to stop in both places.