Question

A semi with a mass of 9,565 kg and going at a velocity of 55 m/s and hits a parked car(992 kg) at rest. If all the momentum is transfered to the car (the semi is now at rest), at what speed does the car move forward (assume an elastic collison, no decimals in the answer and leave no spaces between units and answer).

Answer 1

Speed of car, v₁ = 55 m/s

Step-by-step explanation:

It is given that,

Mass of Semi, m₁ = 9565 kg

Initial velocity of semi, u₁ = 55 m/s

Mass of car, m₂ = 992 kg

Initial velocity of car, u₂ = 0 (at rest)

Since, the collision between two objects is elastic and all the momentum is transferred to the car i.e final speed of semi, v₂ = 0

Let the speed of the car is v₁. Using conservation of linear momentum as :

`m_1u_1+m_2u_2=m_1v_1+m_2v_2`

`9565\ kg* 55\ m/s+992\ kg* 0=9565\ kg* v_1+0`

v₁ = 55 m/s

Hence, the car move forward with a speed of 55 m/s.