Answer:
Explanation:
Applying conservation of momentum law to system of car and truck
their common velocity = their total momentum before collision / total mass
= (0 + 1860 x 19.1 ) / (1400 + 1860)
= 10.8975 m/s
Velocity of car with respect to ground before the collision u₁ = 0
velocity of the car in the frame of Alice u₁ = 0 - 6.11 = - 6.11 m /s
similarly velocity of truck in the frame of Alice = 19.1 - 6.11 = 12.99 m /s
total momentum of system of car and truck in alice's frame
= m₁ u₁ + m₂u₂ , m₁ , m₂ are masses of car and truck and u₁ , u₂ are their velocities in Alice's frame
= 1400 x - 6.11 + 1860 x 12.99
= - 8554 + 24161.4
= 15607.4 kg m/s
velocity of car and truck after collision in Alice's frame
= 10.8975 - 6.11
= 4.7875
total momentum after collision in Alice's frame
= 4.7875 x ( 1400 + 1860 )
= 15607.25
Total momentum before collision in Alice's frame
= Total momentum in Alice's frame after collision
So law of conservation of momentum is obeyed in Alice's frame also.
