Question #9109a

1 Answer
Nov 21, 2016

T_1=541.16N

T_2~~710.35N

T_3=414.55N

Explanation:

enter image source here
From the figure
"Upward vertical component of " T_1 =>T_1sin40

"Horizontal component of " T_1 =>T_1cos40

"Wt of the plank at the mid point"=34xx9.8N

"Wt of the man at the point 0.5m from left end"=725N

"Leftward horizontal force"=T_3

"Upward vertical force on rope at left end" =T_3

The system is in equlibrium

So considering the equilbrium of forces in horizontal direction, we can write

T_3=T_1cos40...(1)

Considering the equilbrium of forces in vertial direction, we can write

T_2+T_1sin40=(725+34xx9.8)N

=>T_2+T_1sin40=1058.2N....(2)

Cosidering the moments of forces about left end we get

2xxT_1sin40=0.5xx725+1xx(34xx9.8)

=>T_1=695.7/(2sin40)N=541.16N

Inserting the value of T_1 in (1)

T_3=541.16xxcos40=414.55N

Inserting the value of T_1 in (2)

=>T_2+T_1sin40=1058.2N

=>T_2+541.16xxsin40=1058.2N

=>T_2=1058.2-541.16xxsin40~~710.35N