An old tire of mass m= 9.0 kg hangs by a rope from a tree. To keep the tire out of the way while mowing the lawn, Jake ties it to the trunk with some string. The string is horizontal, but the rope now makes a 0 = 20° angle with the vertical. Find the tension in the string. (Neglect the masses of the rope and string.) 

a) Draw the free body diagram for the tire. 

b) Find the tension in the string.