Question

A question about momentum in attached file, the answer is B, but how?:/

Answer 1

\[\Delta p=m(v _{f}-v _{i})\]

Answer 2

Watch your units and the sign of velocity.

Answer 3

Thank you but when I did
10 kg (30-20), the answer is 100, not 5 as it's supposed to be that is why I have been struggling lol xD
@JoannaBlackwelder

Answer 4

Mass is not 10 kg.

Answer 5

It is 100 g (1 kg/1000 g) = ?

Answer 6

And if final velocity is 30 m/s, then initial velocity is -20 m/s

Answer 7

When vectors go opposite directions, one is positive and one is negative.

Answer 8

Owwwww Thanks a lot haha I feel like an idiot for not noticing that
I really appreciate it , have a good day (:

Answer 9

@JoannaBlackwelder

Answer 10

No worries. :) Happy studies!

Answer 11

Thanks best of luck and if you ever had any doubts I will be happy to at least try to help (:
Good day

Answer 12

@JoannaBlackwelder