Answer:
3.22 m/s
Step-by-step explanation:
First, use Newton's second law to find the acceleration.
∑F = ma
T − mg = ma
7730 N − (877 kg) (9.8 m/s²) = (877 kg) a
a = -0.986 m/s²
Next, use a constant acceleration equation to find the final velocity.
Given:
Δy = -5.00 m
Δt = 4.00 s
a = -0.986 m/s²
Find: v
Δy = vt − ½ at²
-5.00 m = v (4.00 s) − ½ (-0.986 m/s²) (4.00 s)²
v = -3.22 m/s
The elevator's speed is 3.22 m/s.