3/45 The device shown is used to test automobile-engine valve springs. The torque wrench is directly con- nected to arm OB. The specification for the automo- tive intake-valve spring is that 83 lb of force should reduce its length from 2 in. (unstressed length) to 116 in. What is the corresponding reading M on the torque wrench, and what force F exerted on the torque-wrench handle is required to produce this reading? Neglect the small effects of changes in the angular position of arm OB. 11 55 15" 6" 20 B Problem 3/45 F