# Finding Tension of the boom

## Homework Statement

A 1820N uniform boom is suppoted by a cable. The boom is pivoted at the bottom, and a 1100N object hangs from its end.
The boom has a length L=13 m and is at an angle of 48 degree above the horizontal. At support cable is attached to the boom at a distance of .77L from the foot of the boom and its tension is perpendicular to the boom.
Find the tension in the cable holding up the boom.

## The Attempt at a Solution

1100N * L * cos(48)
+ 1820N* 0.5L * cos(48)
- T * 0.77L
=0

Since L is not relevant in this equation you can just cancel it out.
I got answer to be
1746.691583N
which of course is wrong.
Could you please them me what I am doing wrong.

## Answers and Replies

Doc Al
Mentor
Looks right to me.

ok well...similar to his question

Find the vertical components of the reaction
force on the boom by the floor.

i found that the horizontal component of the reaction
force on the boom by the floor is just Tsin(theta).

so how do i find teh vertical components?

Doc Al
Mentor
Hint: What does the net vertical force on the boom equal?

is it the
Normal of y= Fg(boom)+Fg(block)-Tcos(theata)???

nvn
Science Advisor
Homework Helper
Yes, that's right.