Answer:
The tangential speed of the ball is 11.213 m/s
Explanation:
The radius is equal:
(ball rotates in a circle)
If the system is in equilibrium, the tension is:

Replacing:

Replacing:

Answer: 200 N/m
Explanation:
The Gravitational spring energy(Us) is equal to 1/2kx^2. So we have x as .2 m and Us as 4 N. So 4 N = 1/2 * k * .2^2. So now we solve for K and get 200 N/m.
Magnetic moment of loop is given by the formula



now magnetic field is given here

Now the torque on the loop is given by



so above is the torque on the loop.