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Reply 1


I = mv - mu
Where m is the mass, I is the impulse and v and u are the final and initial speed respectively.

For part b) you want to use Conservation of Momentum law.
i.e. Initial momentum = final momentum

Is that okay?
(edited 7 years ago)
Reply 2
Original post by JLegion
I = mv - mu
Where m is the mass, I is the impulse and v and u are final and initial speeds respectively.

For part b) you want to use Conservation of Momentum law.
i.e. Initial momentum = final momentum

Is that okay?


so i've done 14=2xV - 2x5 right?
Reply 3
Original post by poundsoffat
so i've done 14=2xV - 2x5 right?


Yup
Reply 4
Original post by JLegion
Yup


ok so i get 28=2V
v=14
Original post by poundsoffat
so i've done 14=2xV - 2x5 right?


(2*-5) it's moving in the opposite direction.
Reply 6
Original post by Middriver
(2*-5) it's moving in the opposite direction.


how do you know? does it say in the question?
Original post by poundsoffat
how do you know? does it say in the question?


It's moving in the opposite direction to the direction it received an impulse.
Do you have a drawing for this question?
Reply 8
Original post by Middriver
(2*-5) it's moving in the opposite direction.


Yes, you're correct. My mistake!
Reply 9
Original post by Middriver
It's moving in the opposite direction to the direction it received an impulse.
Do you have a drawing for this question?


yes and after i just put 2 arrows going right
Original post by Middriver
It's moving in the opposite direction to the direction it received an impulse.
Do you have a drawing for this question?



that's my diagram
Original post by poundsoffat

that's my diagram


So using your diagram
image.jpg
Original post by Middriver
So using your diagram
image.jpg


but why is V negative??? how do you know A moves left instead of right?
Original post by poundsoffat
but why is V negative??? how do you know A moves left instead of right?


you need to state a direction from where the impulse was received, then the directions will be relative to that.
Original post by Middriver
you need to state a direction from where the impulse was received, then the directions will be relative to that.


but impulse was received by B??? and given by A?
Original post by poundsoffat
but impulse was received by B??? and given by A?


Yeah but A must also receive an impulse from B.. So it would be the same in the opposite direction.
Original post by Middriver
Yeah but A must also receive an impulse from B.. So it would be the same in the opposite direction.


since when was this a thing?????
Original post by poundsoffat
since when was this a thing?????


https://www.furthermathstutor.co.uk/m1/momentum-and-impulse.html
Read the conservation section.


ok
In an M1 exam on collisions like the one above, you will almost always be asked to find the impulse that one object exerts on the other object. Calculate the change in momentum on the subject object.

so which one's the subject object??????
@Zacken sorry to ask but could you sort me out? xD

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