Asked by mssailormouth
Two people sitting on rolling chairs with little friction push off from each other so that they move apart. On is 60 kg and one is 40 kg. If the 40 kg person recoils at 4.3 m/s, what will the veloocity of the 60 kg person's recoil in m/s
mivi=mfvf
40v...how do I get v with m and t?
mivi=mfvf
40v...how do I get v with m and t?
Answers
Answered by
mssailormouth
or is it 4.3 m/s=-60v
v=-.071??
v=-.071??
Answered by
oobleck
First off, always do a sanity check when you get your answer.
The two people were roughly the same mass, so their velocities should be roughly the same. Your answer was clearly unreasonable.
conserve momentum. Since everything was initially at rest, we need
m<sub><sub>1</sub></sub>v<sub><sub>1</sub></sub> + m<sub><sub>2</sub></sub>v<sub><sub>2</sub></sub> = 0
40 * 4.3 + 60 v<sub><sub>2</sub></sub> = 0
v<sub><sub>2</sub></sub> = -2.87 m/s
The two people were roughly the same mass, so their velocities should be roughly the same. Your answer was clearly unreasonable.
conserve momentum. Since everything was initially at rest, we need
m<sub><sub>1</sub></sub>v<sub><sub>1</sub></sub> + m<sub><sub>2</sub></sub>v<sub><sub>2</sub></sub> = 0
40 * 4.3 + 60 v<sub><sub>2</sub></sub> = 0
v<sub><sub>2</sub></sub> = -2.87 m/s
Answered by
mssailormouth
I was reading the problem that the 40kg recoiled in 4.3 seconds.
I'm tired :(
I'm tired :(