Physic Help??

Question

A mine car, whose mass is 510 kg, rolls at a speed of 0.5 m/s on a horizontal track, as the drawing shows. A 150 kg chunk of coal has a speed of 0.60 m/s when it leaves the chute. Determine the velocity of the car/coal system after the coal has come to rest in the car.

Answer 1

Conservation of momentum

m1V1 + m2V2=(m1+m2)V3

V3= (m1V1 + m2V2)/(m1+m2)
V3=(510 x 0.5 + 150 x 0.60)/(510 + 150)
V3=0.52 m/s

(I'm not sure about the drawing and if angles are involved then...)