77% [El 1:25 l. A squash hall of mass 23 3 falls from a height of] :11 onto a hard surface and rebounds with an initial speed of 1.9 ms". Us: the conservation of energy principle to determine: (a) How high the hall rise: after bouncing? Include an appropriate sketch. [3] (b) How much energy is lost in the impact with the hard surface? [2] Acceleration due to gravity, 3 = 10 ms: Ignore the effects of air resistance