Thread: show time travelled with uniform speed

a lift starts from rest with constant acceleration 4m/s squared. it then travels with uniform speed and finally comes to rest with constant retardation 4m/s squared. the total distance travelled is D an the total time is t

(i) show that the time for which it travelled with uniform speed is
Ö t squared-d

Originally Posted by ronan116

a lift starts from rest with constant acceleration 4m/s squared. it then travels with uniform speed and finally comes to rest with constant retardation 4m/s squared. the total distance travelled is D an the total time is t

(i) show that the time for which it travelled with uniform speed is
Ö t squared-d

here is a very brief outline of an approach:

Motion 1:
u = 0
a = 4 m/s^2




Motion 2:


Motion 3: By symmetry with motion 1

a = -4 m/s^2

v = 0


Given:

.... (1)

.... (2)

Use the motion data to get and in terms of and substitute into equation (2).

Then solve equations (1) and (2) simultaneously.