Answer:
a. 15.4 seconds
b. 0.455 m/s
Explanation:
a. The carousel rotates at 0.13 rev/s.
This means that it takes the carousel 1 sec to make 0.13 of an entire revolution.
This means that time it will take to make a complete revolution is:
1 / 0.13 = 7.7 seconds
Therefore, the time it will take to make 2 revolutions is:
2 * 7.7 = 15.4 seconds
b. Let us calculate the linear velocity. Angular velocity is given as:

where v = linear velocity and r = radius
The radius of the circle is 3.5 m and the angular velocity is 0.13 rev/s, therefore:
0.13 = v / 3.5
v = 3.5 * 0.13 = 0.455 m/s
Linear velocity is 0.455 m/s
Answer:
(E)56.0 m/s
Explanation:
Height =h=-160 m
Because the wallet moving in downward direction
Time=t=7 s
Final speed of wallet=v=0
We have to find the speed of helicopter ascending at the moment when the passenger let go of the wallet.

Where 
Substitute the values



Option (E) is true
When Emmett is lifting a box
vertically, the forces that must be added to calculate the total force are: the
gravitational force, tension force(the force exerted by Emmett to the box and
the force exerted by the box to Emmett), and air resistance force.
Explanation:
Velocity = displacement / time
v = √((58 m)² + (135 m)²) / (12 min × 60 s/min)
v = 0.20 m/s