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a) Calculate the work done on a 4131 kg elevator compartment by its cable to lift it 33.44m at constant speed, assuming friction averages 246 N. J b) What is the work done on the elevator compartment by the gravitational force in this process? J c) What is the total work done on the elevator compartment? J :1) Calculate the magnitude ofthe force needed to bring a 937kg car to rest from a speed of 82 km/h in a distance of 115m (a fairly typical distance for a nonpanic stop). N b) Suppose instead the car hits a concrete abutment at full speed and is brought to a stop in 3.19 In. Calculate the magnitude of the force exerted on the car and compare it with the force found in part (a) Second force = N Ratio of second force to rst force = A person in good physical condition can deliver 100W of useful power for several hours at a stretch, perhaps by pedalling a mechanism that drives an electric generator. Neglect any losses due to generator ine'iciency and practical considerations such as resting time. a) How many people would it take to run a 4.32 kW electric clothes dryer? people b) How many people would it take to replace a large electric power plant that generates 840 MW? people A 523-kg dragster accelerates from rest to a final speed of 132 m/s in 400m and encounters an average frictional force of 1200 N. What is its average power output in watts if this takes 5.52 s? W What is its average power output in horsepower? (Note that 1 hp = 746 W.) hp