power of 50 hpp while the car is travelling a constant speed. If the engine is operating at 80%
efficiency, determine the speed of the car neglecting drag and rolling resistance.
2- An elevator and load have a total mass
of 1600 kg. It is balanced by a
counterweight with a mass of 300 kg.
At a given instant, the hoist has an
upward velocity of 2 mm/ss and an
acceleration of 1.5 mm/ss2. Determine
a. The power output from the motor.
b. If the motor has an efficiency of
εε = 0.80, what is the power
generated by the motor?
3- The roller coaster car has a mass of 800 kg including its passenger and start from the top of a
hill with a speed of vv0 = 3 m/s. Determine the minimum height H of the hill so that the car
travels around the loop without leaving the track. The distance from A to B is 10 m. Neglect
friction , mass of the wheels, and the size of the car.
4- A 180 lbf man bungee jumps off a bridge with an initial downward speed of 6 ft/s . The
bridge is 450 f above the surface of the water and the stiffness of the cord is 100 ibf/f.
Determine the length of cord to which he is attached in order to stop momentarily above the
surface of the water.