Astronaut floats outside spacecraft

[HJ^2]

You can simplify further. And you've lost "v1" this time.

Sorry, again.
v2 = ((v1/Δt) * m1/m2)*Δt

Would that simplify to v2 = ((v) * m1/m2) ??

 

[gneill]

Yes, but you've still used v instead of v1.

You can now proceed to replace variables with their numeric values and obtain a value for v2.

 

[HJ^2]

Alright! v2 = ((v1) * m1/m2)

ends up becoming

v2 = ((-0.195) * (91/3131)

which would make v2 to equal ; -0.00566 ?

 

[gneill]

We dealt with the magnitudes of the velocities during the derivation (no mention of signs designating directions), so at this point it's better to drop the sign on v1 for the calculation of v2, and then assign them both appropriate signs afterwards depending upon your choice of coordinate system if required. However...

I note that the question is asking for speed, so you shouldn't need to specify direction (sign).

Your calculation looks okay, but you've not specified units for the resulting value. Keep in mind that a marker will likely deduct points or just mark the answer wrong if you leave off the units.

 

[HJ^2]

Okay, would that be 0.00566 m/s^2?

 

[gneill]

Okay, would that be 0.00566 m/s^2?

Wrong units. What are the units of velocity?

Also, make sure that you keep enough digits through your intermediate calculation so that you can properly round the final result to the required significant figures. What was the next digit in 0.00566?

 

[HJ^2]

Wrong units. What are the units of velocity?

Also, make sure that you keep enough digits through your intermediate calculation so that you can properly round the final result to the required significant figures. What was the next digit in 0.00566?

0.0055667., and the units are m/s

 

[gneill]

0.0055667., and the units are m/s

You've slipped an extra 5 in there. The units are correct.

 

[HJ^2]

Wow, now it's just simple mistakes. Final answer; 0.005667 m/s. Thanks so much, I spent an unruly amount of time on such a simple problem.