An elevator in a tall building is fitted with a counterweight. The total mass of the car and passengers is 668 kg. The counterweight has mass 512 kg. A motor lifts
the elevator car through a distance of 16.2 m in 15.0 s. The efficiency of the motor is 24.0%. Calculate
the total input of electrical power to the motor
(Show Work)

Aspring with a mass of 2 kg has a damping constant 14 kg/s. a force of 3.6 n is required to keep the spring stretched 0.3 m beyond its natural length. the spring is stretched 0.6 m beyond its natural length and then released. find the position of the mass at any time t. (assume that movement to the right is the positive x-direction and the spring is attached to a wall at the left end.)

Modify the equation fδt=δ (mv) to find the force of friction.

As a pendulum bob swings back and forth several times, the maximum height it reaches becomes less and less. this is because more and more of the pendulum bob's energy is being transformed into a. heat energy b. kinetic energy c. potential energy d. kinetic energy and potential energy