If a 45 kg box collides with a stationary 20 kg box with a force of 75 N, what must be true of the magnitude of the reaction force ?

Why does karst topography exist in some geographic location? a. few climates have enough oxygen b. most regions have rock layers other than limestone c. in most regions, the soil is too thin d. the water is too acidic enough in most places

The diagram shows a boulder rolling down a hill into a valley and then up the opposite hill. at which position does the boulder have the greatest kinetic energy? ab c d

What instrument is used to measure liquid volume?