f? lsin37 -mg? 12(l-lcos 37)-mg(l-lcos 37)= 12? mvA2+ 12m(2vA)2
The solution is vA=6gl5.
When the speed reaches the maximum for the first time, the resultant torque is zero. According to the torque balance conditions, there are
Mg? 12lsinθ+mg? lsinθ=F? lcosθ
Solution: θ = 45.
So, the answer is: 6gl5;; 45