Could you give me some hints at how to answer Q12 part a please?
Force is exerted "on" B. That will cause "change in momentum of B at some rate". Use force-momentum relationship and momentum-time relationship.
well the resultant force is the change in momentum/time interval. So for part a, would I find the change in momentum for truck a?
Rate of change of momentum of A will give you the force "acting on A" ,not the force exerted by A. You are asked to calculate the force "acting on B" which is exerted by A.
Ah so I need to find the change in momentum of the blue line, B?
For part a? Yes.
After solving a and b, you'll see that the momentum lost by A is equal to the momentum gained by B. That's what is expected in part c. The total montemum of the system has been conserved.
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