A 1900-kg car experiences a combined force of air resistance and friction that has the same magnitude whether the car goes up or down a hill at 27 m/s. Going up a hill, the car’s engine produces 47 hp more power to sustain the constant velocity than it does going down the same hill. Calculate at what angle is the hill inclined above the horizontal

An elevator motor lifts a 2750-kg load to a height of 37m in 12.5s. Find the useful power output of the elevator motor, if it also increases the speed from rest to 3.95 m/s. Assume that the total mass of the counterbalanced system is 10,000 kg — so that only 2750 kg is raised in height, but the full 10,000 kg is accelerated.  How much does it cost, in dollars per hour, if the electricity cost is $0.075 per kW⋅h?

If a car (m = 1200 kg) generates 18 hp when traveling at a steady 90 km/h, what must be the combined force exerted on the car due to friction and air resistance? How much power altogether must the car supply to accelerate to 100 km/h in 5.0 s?

The speed of a crate traveling on a horizontal frictional surface changes from vi=13 m/s to vf=11.5 m/s in a distance of d=8.5 m. (A) how long in seconds did it take for the crate to slow by this amount, assuming the acceleration is constant? (B) if the crate has a mass of 1kg, what is the power supplied to the crate by friction? (C) what is the coefficient of kinetic friction between the crate and the surface uk?

(a) How long (in s) will it take an 860 kg car with a useful power output of 42.0 hp (1 hp = 746 W) to reach a speed of 17.0 m/s, neglecting friction? (Assume the car starts from rest.) 3.966 (b) How long (in s) will this acceleration take if the car also climbs a 2.60 m-high hill in the process? 14.02 X s

A sled is initially given a shove up a frictionless 23 degree incline. It reaches a maximum verticle height 1.22 m higher than where it started at the bottom. What was the initial speed?