Put the same lump on a scale on earth and on the moon. One number changes. One does not.
(Fill in the blanks.) The mass of a 300 g object is ____ (a). Its weight on earth is ____ (b). An object that weighs 20 N on earth has a mass on the moon equal to ____ (c). The mass of an object that weighs 5 lb on earth is ____ (d).as printed, page 51
Tap any symbol, here or in a formula, to see what it is and its value.
A small apple pressing on your palm. A newton is about the weight of a hundred grams, so three hundred grams is about three newtons.
Take it to the moon and the scale reads 3.3 N instead of 20. Throw it and it is exactly as hard to get moving. That stubbornness is mass.
A slug is the mass that 1 lb accelerates at 1 ft/s². It weighs 32.2 lb. Odd unit, same idea as the kilogram.
Press play and it reads straight through, scrolling as it goes. Space pauses. ← → move a step. ▶ on a step plays from there.