Isn't it "gravity" this would makes sense because grvaity difines weight
This item is solved through the concept of the conservation of momentum which states that the momentum before and after collision should be equal.
momentum = mass x velocity
(1,600 kg)(16 m/s) + (1.0x10^3 kg)(10 m/s) = (1600 + 1000 kg)(x)
The value of x is 13.69 m/s. Thus, their final speed is approximately letter D. 14 m/s.