The horizontal force is m*v²/Lh, where m is the total mass. The vertical force is the total weight (233 + 840)N.
Fx = [(233 + 840)/g]*v²/7.5
v = 32.3*2*π*7.5/60 m/s = 25.37 m/s
The horizontal component of force from the cables is Th + Ti*sin40º and the vertical component of force from the cable is Ta*cos40º
Thh horizontal and vertical forces must balance each other. First the vertical components:
233 + 840 = Ti*cos40º
solve for Ti. (This is the answer to the part b)
Horizontally
[(233 + 840)/g]*v²/7.5 = Th + Ti*sin40º
Solve for Th
Th = [(233 + 840)/g]*v²/7.5 - Ti*sin40º
using v and Ti computed above.