Q1. A good baseball pitcher can throw a baseball toward home plate at 98 mi/h with a spin of 1590 rev/min. How numerous revolutions does the baseball make on its way to home plate? For simplicity, suppose that the 60 ft path is a straight line.

Q2. A gasoline engine absorbs 2,600 J of heat and performs 1,000 J of mechanical work in each cycle. The total of heat expelled in each cycle?

Q3. A casting of mass 50 kg is placed on a plane inclined at 30° to the horizontal. If the coefficient of friction is 0.4, find the time taken for the casting to slide down the plane a distance of 10 m without any external force being applied. Find out also, the force necessary to give the casting an acceleration of 2 m/s2 up the plane.