A parachutist of mass 68.7 kg jumps out of an airplane at a height of 1080 m and lands on the ground with a speed of 5.9 m/s. The acceleration of gravity is 9.8 m/s^2. How much energy was lost to air friction during this jump? Answer in units of kJ.
Please show work/explanation of how you reached answer. Thank you.
2007-10-21 14:18:14 · 2 answers · asked by splashhhh 1 in Science & Mathematics ➔ Physics
Conservation of Energy provides that the potential energy at the time the jumper jumps will be equal to the kinetic energy at the time the jumper splats plus the friction loss, i.e.,
PE = KE + Efriction
therefore
Efrict = PE - KE
PE =mgh
KE =1/2* m v^2
Efrict = mgh - 1/2*mv^2
Plug'nchug
Note to one significant figure, Efrict ≈ 700 kj
2007-10-21 16:34:59 · answer #1 · answered by Frst Grade Rocks! Ω 7 · 1⤊ 0⤋
Dewd..... You are going to have to set down and study and learn all about work, kinetic energy, potential energy, force, mass, acceleration, and all the rest of it.
If you don't, you're just wasting your time going to school.
Doug
2007-10-21 21:36:31 · answer #2 · answered by doug_donaghue 7 · 0⤊ 0⤋