the motor for a lift in a tall building uses 12000 W of power. The lift and its passengers have a mass of 500kg. The lift motor takes 10s to raise the lift and its passengers through a height of 20m. Work out the percentage efficiency of the lift motor.​

If jesus walked on water, does that mean he swims on land

The 5-kg cylinder is initially at rest when it is placed in contact with the wall b and the rotor at a. if the rotor always maintains a constant clockwise angular velocity v = 6 rad> s, determine the initial angular acceleration of the cylinder. the coefficient of kinetic friction at the contacting surfaces b and c is mk = 0.2.

Awoman holds a book by placing it between her hands such that she presses at right angles to the front and back covers. the book has a mass of m = 1.8 kg and the coefficient of static friction between her hand and the book is μs = 0.67. no attempt 50% part (a) what is the weight of the book, fgb in newtons?