Q1. The clerk pulls with a force of 175.0 N at an angle of 30° with the horizontal. The box has a mass of 31 kg, and the coefficient of kinetic friction between the box and the floor is 0.45. Find the acceleration of the box.
Q2. As part of the safety investigation, two 1400 {rm kg} cars travelling at 23 {rm m/s} are crashed into different barriers. Find the average forces exerted on (a) car that hits a line of water barrels and takes 1.7 {rm s} to stop, and (b) car that hits a concrete barrier and takes 0.4 {rm s} to stop.