Question

A car of mass 1800 kg collides with a truck of mass 5200 kg, and just after the collision the car and truck slide along, stuck together, with no rotation. The car's velocity just before the collision was < 44, 0, 0 > m/s, and the truck's velocity just before the collision was < -21, 0, 20 > m/s. Use the concept of the center-of-momentum reference frame.

Answer 1

Explanation:

Elastic collision is said to occur if the total kinetic energy is not conserved and if there is a rebound after collision

Step one

Analysis of the problem

Immediately after impact the car's velocity was zero making it a perfect elastic collision

Step two

Given

Mass of car M1=1800kg

Mass of truck M2=5200kg

Initial velocity of Car U1=44m/s

Initial velocity of truck U2=21m/s

Final velocity of car V1= 0m/s

Final velocity of truck V2=20m/s

Step three

According to the principle of conservation of momentum

Total momentum before collision

=M1U1+M2U2

Total momentum after impact

=M1V1+M2V2

M1U1+M2U2 =M1V1+M2V2

Substituting our data into the expression we have 1500*44+5800*21=1500*0+5800*20

=66000+1218000=11600

1284000=11600

From the solution the momentum before impact is 1284000Ns

Momentum after impact is 11600Ns

This is indicating that after impact there was loss in momentum as a result of the car having a velocity of zero