A lift of mass 1000 kg is moving up with a speed of 6 m/s. In order to stop it brakes are applied. If the downward acceleration generated is 2 m/s^2, find
(a) The time in which the lift stops.
(b) The distance it covers before coming to a halt.
(c) The tension in to cable supporting lift during the acceleration.
1 Answer | Add Yours
A lift of mass 1000 kg is moving up with a speed of 6 m/s. In order to stop it brakes are applied. Due to this there is a downward acceleration generated of 2 m/s^2.
Taking the downwards direction as positive, initially the lift moves at -6 m/s. The acceleration is 2 m/s^2. If the time it comes to a halt in is t seconds. 0 = -6 +2*t
=> t = 3 s
If the distance covered by the lift before it comes to a halt is s:
-(-6)^2 = 2*2*s
=> s = 36/4 = 9 m
The tension in the cable supporting the lift is the force pulling the lift downwards. This is equal to F = m*a = 2*1000 = 2000 N.
Join to answer this question
Join a community of thousands of dedicated teachers and students.Join eNotes