9. Calculate the horizontal force that must be applied to a 1-kg puck to make it accelerate on a horizontal
friction-free air table with the same acceleration it
would have if it were dropped and fell freely?

What is the measure of a change in an objects velocity?

Avertical clean glass piezometer tube has an inside diameter of d = 1 mm and is used to measure pressure in a horizontal pipe carrying water as shown. due to pressure in the pipe, the water at 20c rises into the tube to a height h. if the water pressure in the pipe is p = 500 pa gauge, estimate the height h: (a) without considering surface tension (b) with surface tension (capillary) effects. the contact angle  can be assumed at 30 deg

Contrast the force of gravity between these pairs of objects: 1-kg mass and a 2-kg mass that are 1 m apart; a 1-kg mass and a 2-kg mass that are 2 m apart; and two 2=kg masses that are 1 m apart. i dont understand.