A 71-kg boy is surfing and catches a wave which gives him an initial speed of 1.6 m/s. He then drops through a height of 1.65 m, and ends with a speed of 8.5 m/s. How much nonconservative work (in kJ) was done on the boy? CkJ Supporting Materials Physical Constants -/3 points V OSCOLPHYS1 7.P.043.WA. My Notes Ask Your Teacher An object with a mass of 60.0 kg is fired with an initial speed of 1.28 x 10 m/s at an angle of 30.0° above the horizontal from a 148 m high cliff (take ground level to be y = 0 m). (a) Determine the initial total mechanical energy in )) of the system of the projectile and the earth. J (b) If when the projectile is at its maximum height of y = 319 m, it is traveling 90.7 m/s, determine the amount of work (in )) that has been done on the projectile by air resistance. ?? (c) What is the speed (in m/s) of the projectile immediately before it hits the ground, if air resistance does one and a half times as much work on the projectile when it is going down as it did when it was going up? Om/s