With what acceleration does the lift move during braking if it stops 7 seconds after the start of braking?

With what acceleration does the lift move during braking if it stops 7 seconds after the start of braking? The initial speed of the elevator is 3.5 m / s. The movement of the elevator car during braking is considered uniformly accelerated.

Acceleration (a) is found by this formula:
a = V-Vo / t
where V is the final speed
Vo-initial speed
t-acceleration time
To find the acceleration, we just need to substitute the values of speed and time
a = 0-3.5 / 7 = -3.5 / 7 = -0.5 (m / s ^ 2)
Answer: a = -0.5 (m / s ^ 2)