Q. A clerk moves a box of cans down an aisle by pulling on a strap attached to box. The clerk pulls with a force of 178 N at an angle of 24° with the horizontal. The box has the mass of 40 kg, and the coefficient of kinetic friction between box and floor is 0.45. Find out the acceleration of the box.
Q. Assume you are swimming in a river while a friend watches from the shore. In calm water, you swim at a speed of 1.25 m/s. The river has a current that runs at a speed of 1m/s. Note that speed is the magnitude of velocity vector. The velocity vector tells you both how fast something are moving and in which direction it is moving. If you are swimming upstream (i.e. against the current, at what speed does your friend on shore see you moving?