Question

A 4350 kg truck, driving 7.39 m/s, runs into the back of a stationary car. After the collision, the truck moves 4.55 m/s and the car moves 11.5 m/s, both in the same direction. What is the mass of the car?

Answer 1

Answer:

The mass of the car is 1074.26 kg.

Explanation:

Let the mass of the car be x.

Given:

Mass of truck, $M=4350$ kg

Initial velocity of truck, $u_1=7.39$ m/s

Initial velocity of car,$u_2=0$ m/s

Final velocity of truck, $v_1=4.55$ m/s

Final velocity of car, $v_2=11.5$ m/s

When two bodies collide with no external force acting on the system, their total momentum remains conserved.

Therefore, initial momentum = final momentum

$Mu_1+x u_2=Mv_1+xv_2\\4350\times7.39+0=4350\times 4.55+11.5x\\32146.5=19792.5+11.5x\\11.5x=32146.5-19792.5\\11.5x=12354\\x=\frac{12354}{11.5}=1074.26\textrm{ kg}$

Hence, the mass of the car is 1074.26 kg.

Answer 2

Answer:

1074.26 kg

Explanation: