An escalator is needed to carry 80 passengers per minute avertical distance of 7.0 m. Mass of each passenger is 65kg. a) Calculate the total amount of work b) What is the power (in kilowatts) of motor needed? c) Express this in horsepower (hp) d) What is the power in Kilowatts of the motor needed if 35%of the power is lost to friction and other losses. An escalator is needed to carry 80 passengers per minute avertical distance of 7.0 m. Mass of each passenger is 65kg. a) Calculate the total amount of work b) What is the power (in kilowatts) of motor needed? c) Express this in horsepower (hp) d) What is the power in Kilowatts of the motor needed if 35%of the power is lost to friction and other losses.
Explanation / Answer
given vertical distance = h= 7.0m mass of each passenger = m = 65kg total massof passengers travelled in escalator = M =65*80 = 5200kg hence work done = W = Mgh = 5200*9.8*7.0 =356720J = 3.5*105 J power = W/t = 3.5*105 J/1*60 =5.8*103 W in horse power = 5.8*103W/746 = 7.7hp