A boy takes sand and fills it gently at a constant rate of 50 g/s on a horizontal belt moving steady at 40 cm/s. Find the force in newtons on the belt exerted by the sand.

Using a pedometer, you walk 3000 steps in 20 minutes, so your speed is 150 steps/min. each of your steps is 0.7 m long. what is your speed? 150 steps/min=/s=/h

The protons in a nucleus are approximately 2 ✕ 10^−15 m apart. consider the case where the protons are a distance d = 1.93 ✕ 10^−15 m apart. calculate the magnitude of the electric force (in n) between two protons at this distance.

Atoms in a molecule are bonded together by sharing gaining or losing_