A descending elevator of mass 420 kg is uniformly decelerated to rest over a distance of 4 m by a cable in which
the tension is 5519 N. The acceleration due to gravity is 9.8 m/s 2
a) Calculate the speed vi of the elevator at the beginning of the 4 m descent. Answer in units of m/s
b) Calculate the acceleration of the elevator during the fourth 5 s interval (from 15 s to 20 s). Answer in units of m/s 2 .
c)What is the velocity of the elevator at the end of the fourth 5 s interval (at 20 s)? Answer in units of m/s.