2. A strongman is demonstrating his strength by pulling a horizontal rope attached to a wrecking ball of weight 2000N suspended from a crane. At maximum effort, the man is able to deflect the suspending cable at an angle of 60° to the horizontal.
(a) Draw a diagram to represent the forces.
(b) calculate the tension on the cable T_{1}.
(c)
Calculate the strength of the man.

Fig 1

Answer

(a)

(b) The force T_{1} can be resolved into two forces at right angles to each other
T_{1h} and T_{1v}.

Recall Sin θ = ^{opposite}/_{hypotenuse} and Cos θ = ^{adjacent}/_{hypotenuse}

so Sin 60° = ^{T1v}/_{T1} -----Eq 1

and Cos 60° = ^{T1h}/_{T1} --- Eq2

From Eq1 T_{1} = = ^{T1h}/_{Cos 60°} --- Eq3

From Eq2 T_{1} = ^{T1v}/_{Sin 60°}--- Eq4

Fig 2

Figure 2 can be redone to show the components of Fg (Fv and Fh)

The ladder is in equilibrium:
Recall from Newton's First and Second Laws the conditions for static equilibrium: