Answer:
10.93 rad/s
Explanation:
If we treat the student as a point mass, her moment of inertia at the rim is
So the system moment of inertia when she's at the rim is:
Similarly, we can calculate the system moment of inertia when she's at 0.456 m from the center
We can apply the law of angular momentum conservation to calculate the post angular speed when she's 0.456m from the center:
Answer:
The net force = 0
Explanation:
The given information includes;
The mass of the crate = 250 kg
The way the helicopter lifts the crate = Uniformly (constant rate (speed), no acceleration)
In order to pull the crate upwards, the helicopter has to provide a force equivalent to the weight of the crate keeping the helicopter on the ground.
The weight of the crate = The mass of the crate × The acceleration due gravity acting on the crate
The weight of the crate, ↓ = 250 kg × 9.81 m/s² = 2,452.5 N
The force the helicopter should provide to just lift the crate, ↑ = The weight of the crate = 2,452.5 N
The net force, =
↑ -
↓ = 2,452.5 N - 2,452.5 N = 0
The net force = 0.