a 28 kg mass suspends from a light rope 18 m long & is held to one side by the horizontal force, f, as shown below.
the distance, s, 11.1 m. find f.

215.15 N

Explanation:

If we draw a free body diagram of the mass we will have the following:

(1)

(2)

Where is the tension force of the rope, the mass, the acceleration due gravity and is the weight.

On the other hand, we can calculate as follows:

Where and

(3)

Now, we firstly need to find from (2):

(4)

(5)

Substituting (5) in (1):

(6)

Finally:

c) up is the direction the magnetic force is acting on the charge.