Acar moves horizontally with a constant acceleration of 3 m/s2. a ball is suspended by astring from the ceiling of the car. the ball does not swing, being at rest with respect to thecar. what angle does the string make with the vertical?

A12-g wad of sticky clay is hurled horizontally at a 100-g wooden block initially at rest on a horizontal surface. the clay sticks to the block. after impact, the block slides 7.5 m before coming to rest. if the coefficient of friction between the block and the surface is 0.65, what was the speed of the clay immediately before the impact?