Imagine you push a book across an incredibly slippery surface. It slides right across because there is no friction. Next, you push the same book across a rougher surface that exerts friction.

Part of a control linkage for an airplane consists of a rigid member cb and a flexible cable ab. if a force is applied to the end b of the member and causes it to rotate by θ = 0.5°, determine the normal strain in the cable. originally the cable is unstretched.