2. When tightening a bolt, you push perpendicularly on a wrench with a force of 165 N at a distance of 0.140 m from the center of the bolt. (a) How much torque are you exerting In newton x meters (relative to the center of the bolt)? (b) Convert this torque to footpounds. 7. Two children of mass 20.0 kg and 30.0 kg sit balanced on a seesaw with the pivot point located at the center of the seesaw. If the children are separated by a distance of 3.00 m, at what distance from the pivot point is the small child sitting In order to maintain the balance? 8. (a) Calculate the magnitude and direction of the force on each foot of the horse in Figure 9.31 (two are on the ground), assuming the center of mass of the horse is midway between the feet. The total mass of the horse and rider is 500kg. (b) What is the minimum coefficient of friction between the hooves and ground? Note that the force exerted by the wall is horizontal. CG Fwall W 1.2 m 1.4 m 0.35 m (a) (b)17. To get up on the roof, a person (mass 70.0 kg) places a 6.00-m aluminum ladder (mass 10.0 kg) against the house on a concrete pad with the base of the ladder 2.00 m from the house. The ladder rests against a plastic rain gutter, which we can assume to be frictionless. The center of mass of the ladder is 2 m from the bottom. The person is standing 3 m from the bottom. What are the magnitudes of the forces on the ladder at the top and bottom? 19. What is the mechanical advantage of a nail pullersimilar to the one shown in Figure 9.23 where you exert a force 45 cm from the pivot and the nail is 1.8 cm on the other side? What minimum force must you exert to apply a force of 1250 N to the nail? T NI UV\\', \\'luvlulll | N Fii Io= ol Figure 9.22 A nail puller is a lever with a large mechanical advantage. The external forces on the nail puller are represented by solid arrows. The force that the nail puller applies to the nail (F,) is not a force on the nail puller. The reaction force the nail exerts back on the puller (Fy) is an external force and is equal and opposite to F,,. The perpendicular lever arms of the inout and output forces are i and [