1. In a competition, a man pushes a block of mass 50 kg with constant speed 2 m s-1 up a smooth plane inclined at 30° to the horizontal. Find the rate of working of the man. [Take g = 10 m s-2.]
2. An athlete putts a shot of mass 7 kg a distance of 20 m. Show that the athlete must do to at least 700 J of work to achieve this. [ Ignore the height of the athlete and take g = 10 m s-2.]