posted by Jim .
Pulling the string on a bow back with a force of 28.7lbs, an archer prepares to shoot an arrow. If the archer pulls in the center of the string, and the angle between the two halves is 138 degrees, what is the tension in the string?
Consider the forces acting where the arrow is held. Perform a force balance along the direction of the arrow. F = 28.7 pulls the string and the string has tension T on both sides of the arrow, inclined 69 degrees to the horizontal.
2 T cos 69 = 28.7 lb
Solve for T