Virtual Work Method

The lever force F moves down by 200 . Hence, the work done by it is

F (200 ) .

Point C moves down to C'. Hence, the work done by the punch force is

-F_p (CC').

Let us calculate CC'.

AC=2(200) cos 60⁰

AC'=2(200) cos (60⁰-)

Hence,

CC'=AC'-AC=400 (cos 60⁰cos dq + sin 60⁰sin )-400 cos 60⁰

For very small virtual displacement,

cos =1 and sin =