Answer:
The average power delivered by the elevator motor during this period is 6.686 kW.
Explanation:
Given;
mass of the elevator, m = 636 kg
initial speed of the elevator, u = 0
time of motion, t = 4.5 s
final speed of the elevator, v = 2.05 m/s
The upward force of the elevator is calculated as;
F = m(a + g)
where;
m is mass of the elevator
a is the constant acceleration of the elevator
g is acceleration due to gravity = 9.8 m/s²

F = (636)(0.456 + 9.8)
F = (636)(10.256)
F = 6522.816 N
The average power delivered by the elevator is calculated as;

Therefore, the average power delivered by the elevator motor during this period is 6.686 kW.
What causes the ballon to fly away is the air pushing out of the balloon also tied in with air pressure
Answer:
3.71 m/s in the negative direction
Explanation:
From collisions in momentum, we can establish the formula required here which is;
m1•u1 + m2•v2 = m1•v1 + m2•v2
Now, we are given;
m1 = 1.5 kg
m2 = 14 kg
u1 = 11 m/s
v1 = -1 m/s (negative due to the negative direction it is approaching)
u2 = -5 m/s (negative due to the negative direction it is moving)
Thus;
(1.5 × 11) + (14 × -5) = (1.5 × -1) + (14 × v2)
This gives;
16.5 - 70 = -1.5 + 14v2
Rearranging, we have;
16.5 + 1.5 - 70 = 14v2
-52 = 14v2
v2 = - 52/14
v2 = 3.71 m/s in the negative direction
A force is a push or pull to an object
Explanation:
a) Power = work / time = force × distance / time
P = Fd/t
P = (85 kg × 9.8 m/s²) (4.6 m) / (12 s)
P ≈ 319 W
b) P = Fd/t
0.70 (319 W) = (m × 9.8 m/s²) (4.6 m) / (9.6 s)
m = 47.6 kg