A 6,600 kg train car moving at +2.0 m/s bumps into and locks together with one of mass 5,400 kg moving at −3.0 m/s . What is their final velocity? −1.0 m/s

−0.25 m/s

+0.50 m/s

+2.5 m/s

option B is the correct option

Explanation:

According to momentum conversion,

momentum of one car= 6600×2=13,200kgm/s

momentum of another car=5,400×(-3)=16,200kgm/s

Then,

Momentum of second car-momentum of first car

=16,200-13200

=3000kgm/s

mass of first car -mass of second car

=6600-5400

=600kg

final velocity=3000/600=2.5 m/s

massxgravity x heght=weightxheight= pe

4900=490xh

h=10