# Physics Momentum

Could someone show me how to solve this question? Does A and B stick together after the collision?

Hi!
I think the bodies will stick post collision as itâ€™s inelastic collision where bodies stick and have a same final velocity also in inelastic collision momentum is conserved but K.E isnâ€™t.
Do you please mind sharing the answer as iâ€™m not sure whether my calculation is correct or not.

I thought so too but I didnâ€™t get an answer to what they said. The answer is 288N, if it matches, please show me!

Hi!
I got the value this is how i did it:
They have asked us the force dissipated so in order to calculate it we need â€śmâ€ť and â€śaâ€ť as F=m.a
the initial velocity was 15ms^-1 and the final velocity is 3ms^-1 post collision. thus, acceleration
a=v-u/t=3-15/0.5=-24ms^-2(negative because the body slowed down)
F=12*24=288N(considering only the magnitude).
Hope this helps!

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oh hereâ€™s how i found 288N:

p is conserved so:
delta p1 = F1 * delta t
so F1 = (m1 * delta v1) / delta t
so F1 = 12 * (3-15) / 0,5 = 288N

We consider the magnitude of delta V1 = +12

I think Ujjwalâ€™s way is better

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hi!
Juliette i think your way is totally correct as i was getting a negative value so, i eventually considered only the magnitude as Forces are vectors.

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great catch let me change my answer i did Vi-Vf instead of the other way around, i guess weâ€™ll just use the magnitude then?

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Thank you so much! Iâ€™ll keep this method in mind too when im rushed for time!

This makes a lot of sense! I think I went wrong in the last calculation where I used both the masses A and B to get Force

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