A vaulter holds a 20.7 N pole in equilibrium by exerting an upward force, U, with his leading hand, and a downward force, D, with his trailing hand. Let L1 = 0.71 m, L2 = 1.5 m, and L3 = 2.21 m. What are the magnitudes of U and D?

Answer 1

I assume that the pole is horizontal as the vaulter runs up to the bar. I cannot do the problem for you without some idea of the location of the quoted distances in relation to his (or her) hands and the length of the pole.

In any case, set the total moment about either hand equal to zero, and assume the weight of the pole acts through the middle. The will let you solve for the other force.