A projectile of mass 0.799 kg is shot straight up with an initial speed of 16.2 m/s. (a) How high would it go if there were no air resistance? (b) If the projectile rises to a maximum height of only 7.24 m, determine the magnitude of the average force due to air resistance.
![(a) A 500 g block is shot on the surface in FIGURE 3 with an initial speed of 0.5 ms−1. How far will it go if the coefficient of friction between it and the surface is 0.150? [3 marks] (b) A 0.25 hp motor is used to lift a load at the rate of 5.0 cms−1. Determine the mass of the load at this constant speed? [1 hp = 746 W] [3 marks] (c) At sea level, a nitrogen molecule in the air has kinetic energy of 6.2×10−21 J. Its mass is 4.7×10−26 kg. If the molecule could shoot straight up without striking other air molecules, how high would it rise? [2 marks]](https://www.doubtrix.com/uploads/editor/8844506183SExwnDCwBv.jpg)
