+/- 500 kg m/s
Change in momentum is due to change in velocity:
(v1 denotes velocity before and v2 velocity after). The change in velocity is cause by the acceleration "a" due to the force applied. We are not told which direction the force acts: is against the current movement (deceleration), or in same direction as the movement of the wagon (acceleration). So I will keep both options open by using +/- in the calculation. The v2 can after appliying the acceleration for a time "t" is written as:
and so the change in momentum is:
The absolute change in momentum is 500 N m/s. The change can be an increase or decrease - we can't tell from the problem statement alone.
what type of charge does it have? negative
there is no correct list among the choices you've provided.
the list might look something like this:
-- baby human
-- soprano singer
-- tenor singer
-- baritone singer
-- baritone horn
-- bass singer
since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.