physics question.10 pts best answer?
November 3rd, 2009 Posted by: admin
Two figure skaters, one weighing 675 N and the other 750 N, push off against each other on very smooth ice.
1. If the heavier skater travels at 1.20 m/s, how fast will the lighter one travel?
2. How much kinetic energy is “created” during the skaters’ maneuver?
3. Where does this energy come from?
By: K M
Tags: Physics, Skater, Travels
November 5th, 2009 at 07:29
This is how I’ve worked it out but I could be wrong - it’s been a long time since I did this sort of thing!
1) F=MA (force = mass x acceleration)
F= 750 x 1.2
F= 900
900 = 675 x A
900/675 = A
A = 1.3333333 (recurring)
The lighter skater is travelling at 1.333333 m/s
2)
E = 1/2 x m x v squared (Energy = 1/2 x mass x velocity squared)
E = 1/2 x 675 x 1.77777778
E= 600 J
E = 1/2 x m x v squared
E = 1/2 x 750 x 1.2
= 410.79 J
600 + 410.79 = 1010.79 J
3) Kinetic energy is transferred from the potential energy of the opposing skater. Energy isn’t created.