In: Physics
A lift accelerates upwards from rest to a speed of 5.5 m s−1 in a certain time, ∆t. At that time, the ratio of its kinetic energy to the gravitational potential energy it has acquired is 0.33. What is the value of the time interval, ∆t?
Gravitational acceleration = g = 9.8 m/2
Mass of the lift = m
Initial speed of the lift = V1 = 0 m/s (At rest)
Final speed of the lift = V2 = 5.5 m/s
Time period in which the the lift accelerates = t
Acceleration of the lift = a
Height gained by the lift as it accelerates = H
Potential energy acquired by the lift = PE
Kinetic energy acquired by the lift = KE = 0.33PE
t = 1.7 sec
Value of the time interval = 1.7 sec