Pam has a mass of 35.2 kg and she is at rest on smooth, level, frictionless ice. Pam straps on a rocket pack. The rocket supplies a constant force for 19.4 m and Pam acquires a speed of 63.4 m/s. What is the magnitude of the force in N? And what is her final kinetic energy (in joules)?
2006-12-15 10:58:58 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics
First of all Robert, it's a practice problem, second, I have tried it and want to know if it's right. Hold your opinions to yourself, it's not polictics.
2006-12-15 11:15:52 · update #1
Saying that “Pam acquires speed of 63.4 m/s” is the same as “Pam acquires a kinetic energy of ½ m vv”.
Kinetic energy acquired is 0.5 x 35.2 x 63.4 x 63.4 J
This energy is given to Pam by a force F which moves through a distance of 19.4m
Work done or energy given by this force = F x 19.4 J
Therefore, 19.4 F = 0.5 x 35.2 x 63.4 x 63.4.
F = 3647 N.
2006-12-15 12:54:03 · answer #1 · answered by Pearlsawme 7 · 0⤊ 0⤋
I don't want to make any specific accusations, but it looks like a lot of people here are summoning the entire yahoo population to do their homework for them. Physics is a difficult subject--the only way to master it is to struggle a bit.
It's a lot like lifting weights. If you go to the gym and get someone to help you pick up all the heavy weights, you'll get through your exercise routine unscathed. But you won't gain any muscle mass doing so. The only way to build muscle is to lift the weights yourself. It's pretty strenuous at first, but if you keep at it, you get stronger and stronger.
Apply the same principle to studying math and physics.
2006-12-15 19:09:10 · answer #2 · answered by robert 3 · 0⤊ 1⤋
You can get the acceleration from V^2 = Vo^2 + 2*a*s.
Then F = m*a will give you the force.
KE = (1/2)*m*v^2
2006-12-15 19:40:11 · answer #3 · answered by sojsail 7 · 1⤊ 0⤋