29:006 Solutions Bloomfield 5e Page 83

29:006 Solutions Bloomfield 5e Page 83 Exercise 6: When the line of the force you apply passes through the axis of rotation, the force does not produce a torque. Exercise 7: Again, when you apply the force right at the hinge, the torque is very small because the lever arm is very short. Exercise 8: When your hands are outstretched and you are holding a weight, the torque produced by the weight is very large because the lever arm is as long as it can be. If you hold the weight with your arms close to your body, you minimize the lever arm and the torque. Exercise 11. If you put a nut in the hinged side of the door, you are using the full width of the door as the lever arm, thus producing a large torque. Exercise 12: When the cutting blades are near the pivot, the lever arm of the pliers is as large as possible, thus maximizing the torque. Exercise 14: By making the poles very long, their lever arm is long and this effectively increases the rotational inertia of the tightrope walker and also lowers his effective center of gravity. Both of these effects make it more difficult for gravity to tip him over. Exercise 16: The length of the bottle opener provides a long lever arm. Exercise 17: The longer the handles, the longer the lever arm, the more torque can be applied. Exercise 18: The further out you get on the tree limb, the longer the lever arm, making it easier for gravity to break the limb where it connects to the tree, and as a result you fall down. Exercise 19: A long crowbar mean you have a long lever arm, thus increasing the torque that can be produced by a force.