When cylinder-head bolts in an automobile engine are tightened the critical quantity is the ?torque? applied to the bolts. Why is the torque more important than the actual ?force? applied to the wrench handle?
Solution 1DQ Step 1 of 3: For the rotational effect of force ,the magnitude and direction of the force applied are important and also the point on the body where the force is applied. As the resultant rotational force know as torque is given by, = Fl Where is torque, F is the applied force and l is the distance at which force is applied. Step 2 of 3: Now let us consider the wrench which is being used to tighten the bolts in automobile as shown in the figure below, The force applied near to center at a will do very less work or in other words torque will be less as the distance from axis ‘a’ is small. Similarly the same force applied at ‘b’ (end of the handle) will do more work compared to same force applied at ‘a’, as the distance ‘b’ is larger, hence resultant torque will be greater. Whereas same magnitude force(F ) applied at b ( end of the handle), will not c perform any sort of work or the torque will be zero.