Recent content by OscarF

They didn't make the worksheet - It's an AQA physics gcse practice question. My teacher's a nice person though - would be fine if I wanted to contest the question!

Hmm... The output results as 0.8 m/s if I do that... Due to the nature of the question, it just feels unlikely that it's a mistake - but you never know - so I have a few options. Either, I just keep it as it is - the answer fine, done and dusted or I add the answer but also add a little note to...

I do have an equation for the first cart - let me just check what that gives as a result in this instance

Hmm... I personally wouldn't expect such a twist in a homework like this... Do you think the solution would be to write something like this event isn't possible because...

I just realized... obviously the momentum will not be the same... because for trolley B pre-collision the momentum would be 0 and afterwards it will be whatever 120*4.8 is...

Good point! Will check now, one second.

Well, from a bit more digging around I came up with these two calculations: (For the elastic scenario) V2f=(2m1/(m1+m2))*v1i (For the inelastic scenario) V2f=(m1v1)/(m1+m2) Which led me to the answers: i) 4.8 m/s ii) 2.4 m/s

So to cut to the chase, I missed my class' lesson on momentum - have tried to catch up, quite successfully but am baffled about this question. I know the conservation of momentum etc. but after trying for ages it's just not happening this question so any help would be much appreciated, Oscar.

great, makes sense! And finally, part d, is it basically just the same graph but with the drag values doubled?

oh ok, makes sense. Just quickly for question c, would the terminal velocities be 400N and 1000N

but why is her weight 600N, if we had done this at a different point we would just be concluding that her weight is 800N for example.

so then if the weight were 600N, that point would be terminal velocity. I still don't understand why 600N MUST be the parachutist's weight though.

When the parachutist is traveling at 5/ms

Would that value be 600N?

yes... I still don't understand though how the weight is found out from that being that we are only given speed. Although, I guess that's the next step - I'm just stumped.