A pole-vaulter has his center of mass 1.00 m above the ground. He starts running from rest, accelerating at 2.5 m/s², and travels 10.0 m before he begins to use the pole. How high above the ground can the athlete raise his center of mass? A) 1.6 m. B) 2.6 m. C) 3.6 m. D) None of the above is correct. E) More information is needed to work out the answer.

Question

Quizplus · Accepted Answer

The athlete's kinetic energy from running is converted into potential energy. Using the equation $ v^2 = u^2 + 2as $, the final velocity $ v $ is found to be 7 m/s. The potential energy at the highest point is $ mgh $, where $ h $ is the height above the initial center of mass. Solving $ \frac{1}{2}mv^2 = mgh $ gives $ h = \frac{v^2}{2g} = \frac{49}{19.6} = 2.5 $ m. Adding the initial 1 m, the total height is 3.5 m, which rounds to 3.6 m.

A Pole-Vaulter Has His Center of Mass 1