Question
An elevator of mass 400kg supported by a cable which can withstand a maximum tension of 4400N, is going down with constant velocity 2m/s. Will it be wise to stop the elevator in l.6m. Take g = 9.8m/s2.
Solution
Given,
Initial velocity, u = 2m/s
Final velocity, v = 0 m/s
Distance, s = 1.6m
The acceleration of elevator is,
The tension in the cable is,
T = m(g - a)
= 400[9.8 - (-1.25)]
= 4420 N
The tension in the cable is greater than the strength of string, therefore the cable will break.
Thus it will not be wise to stop the elevator within 1.6m.
