Work and Energy Legacy Problem #13 Guided Solution

A good problem solver reads a problem carefully, identifying the known and the unknown information, and then uses an understanding of physics principles and mathematical relationships in order to plot a strategy for getting from the known information to the unknown information. Here we're told about Li Ping-Far, a esteemed Chinese ski jumper who has an M, or mass, of 59.6, a V of 23.4 meters per second, and an H of 44.6 meters. We're asked to determine the total mechanical energy of Li Ping-Far. When asked to find the total mechanical energy, they're asking us to determine the sum of the two forms of mechanical energy, the sum of the kinetic energy and of the potential energy. So to solve this problem, we will first need to calculate two preliminary quantities, the Ke and the Pe. To calculate the Ke, we use the equation Ke equals one-half mv squared, where the M is 59.6 kilograms and the V is 23.4 meters per second. Plugging into this equation, we get 16,317 joules is our Ke. I'm going to write that down. The Pe can be calculated by using the equation Pe equals mgh, where the M is 59.6 kilograms, the G is 9.8 newtons per kilogram, and the H is 44.6 meters. Plugging numbers into this equation, I get 26,099.96 joules. Now to find the total mechanical energy, I have to sum these two quantities together. And when I do, I get roughly 42,367. I'll round that to two significant digits, and the answer is 4.24 times ten to the fourth.