Solve Hanging Sign Problem: Tension in Two Ropes

[miewann]

1. Ok, i need help on this question:
Find the tension in two ropes holding up a sign. The sign weighs 59 kg. The hypotenuse of the ropes holding the sign is the ceiling, with the left angle of 24 degrees, and the right is 72 degrees.



2. How do i solve this?



3. i think i start out with T1+T2+Mg=0

 

[HallsofIvy]

You are saying then that the sign is held by two ropes attached to the sign at a single point? And the ropes meet the ceiling at angles of 24 and 72 degrees? If so then "hypotenuse" is the wrong word- this is not a right triangle since 24 and 72 do not add to 90 degrees.

No, you do NOT start out with T1+ T2+ Mg= 0. T1 and T2 are forces in the direction of the 2 ropes and -Mg is the force straight down. You need to use trig functions to separate the T1 and T2 into horizontal and vertical components. The horizontal components add to 0 and the vertical components add to -Mg (so your equation above is correct if you use the vertical components of T1 and T2).

 

[miewann]

ok, so I'm sorry, i have no idea what I'm doing. is it 24cosT2 and 72cosT1?

 

[miewann]

nevermind i figured it out