A 3,00 kg truck moving at + 10 m/s hits a 1,000 kg parked car in which moves off at + 15 m/s what is the velocity of the truck

Momentum before collision = momentum after collision

If

m₁ = 300 kg

v₁ = 10 m/s

m₂ = 1000 kg

v₂ = 0 as the car was parked

momemum before collision =

m₁ v₁ + v₂ m₂ = 3000kgm/sec

momentum after collision = m₁ v₃ + v₄m₂=

300v₃+15m/sx 1000kg

now from the law of conservation of momentum

momentum before collision = momentum after collision

3000kgm/s = 300v₃ + 15000kgm/s

-15000+3000 = 300v₃

-12000=300v₃

v₃ = - 40m/s

the velocity of truck after collision is 40m/s and the negative sign indicates that its a recoil velocity.