A uniform ladder stands on a rough floor and rests against a frictionless wall as shown in the figure. N mg b Since the floor is rough, it exerts both a normal force N and a frictional force f on the ladder. However, since the wall is frictionless, it exerts only a normal force N on the ladder. The ladder has a length of L= 4.50 m, a weight of W = 55.5 N, and rests against the wall a distance d = 3.75 m above the floor. If a person with a mass of m= 90 kg is standing on the ladder, determine the following. (a) the forces exerted on the ladder when the person is halfway up the ladder (Enter the magnitude only.) N = 937.5 N 588.6 X N = Determine a good point about which to sum the torques and then see if you can apply the condition for rotational equilibrium about that point that will allow you to determine N, the normal force exerted on the ladder by the wall. You may need to use your knowledge of trigonometry to determine the angle between the ladder and the floor. N 468.8 x See if you can apply the condition for translational equilibrium to horizontal forces acting on the ladder in order to obtain a relationship between f and N and hence determine f. N (b) the forces exerted on the ladder when the person is three-fourths of the way up the ladder (Enter the magnitude only.) N = 937.5 N N 882.9 X Using the point specified in part (a) as the point about which to sum the torques, see if you can apply the condition for rotational equilibrium that will allow you to determine N, the normal force exerted on the ladden by the wall. N Go to Settings to activate Windows. 882.9 X f1=See if you can apply the condition for translational equilibrium to horizontal forces acting on the ladder in order to obtain a relationship between fand W and hence determine f. N. N, Additional Materials