Answer:
Explanation:
Given that,
The elevator slow to stop, this shows that it is decelerating and the final velocity is 0
v = 0m/s
Constant deceleration
a = -1m/s²
It is negative because it is deceleration
The distance the elevator descend is 4.5m
S=4.5m
Then, we want to find the time the elevator spent before stopping
Using the equation of motion
v = u + at
v² = u² + 2as
Where
v is final velocity
u Is initial velocity
a is the deceleration
s- is distance traveled
From here we can find the initial velocity of the elevator
v² = u² + 2as
0² = u² - 2 × 1 × 4.5
0 = u² - 9
u² = 9
u = √9
u = 3m/s
The initial speed is 3m/s
Then, to find the time taken, we can use the first equation
v = u + at
0 = 3 - 1 × t
0 = 3 - t
t = 3 seconds
The time taken before the elevator stop is 3 secs
