Question

How do you get F= (p2+p1)/∆t from F=(p2-p1)/∆t if the direction of motion is reversed in the final momentum? (this is a question on momentum)
Shouldn't it be F=(-p2-p1)/∆t?

Answer 1

Answer:

direction is reversed so -ve sign will be applied due to impulsive force

Explanation:

see force = change in momentum per unit time

so F = d( p2-p1 0/ dt

as the direction of motion is changed so momentum becomes

  p2 - (-p1) = p2 + p1

and hence the impulsive force is increased

i.e  F=  d(p2+p1)/dt

and it shouldn't  be -p2-p1  as u mentioned bcoz the the change in initial momentum is called final momentum as so -ve sign will be only applied to p1

Thank u . hope it helps