3. Sharon pushes a tall box across the floor. Her arms (and therefore her push force) of F = 400 N make a 0 = 30 angle with the horizontal. Since the box rests on ball bearings it is essentially frictionless. Sick of her job, Sharon decides to give the box a brief shove lasting only t = 0.2 seconds. Find the velocity (magnitude and direction) of the box at the completion of Sharon's shove, assuming (a) the box's weight is 490 N, and (b) the box's weight is 122.5 N. In both cases, the box starts from rest.