Question

A car of mass 200 kg travelling at 20 m/s crashes into a truck of mass
2000 kg travelling at 2.5 m/s in the same direction as the car. After the
collision the car bounces back at a speed of 5 m/s. Find the speed of
the truck after the impact.​

Answer 1

Answer:

$4 {m.sec}^{ - 1}$

Step-by-step explanation:

Momentum Of Car Before Collision:-

Mass x Intial Velocity or m1u1:-

$m1u1 = )mass \times velocity \\ = )200 \times 20 \\ = )4000kg.m.se {c}^{ - 1}$

Momentum Of Truck Before Collision:-

Mass x Intial Velocity or m2u2:-

$m2u2 = mass \times velocity \\ = )2000 \times 2.5 \\ = )5000kg.m.se {c}^{ - 1}$

AFTER COLLISION

Momentum Of Car After Collision:-

mass x Final velocity or m1v1:-

$m1v1 \: or \: mass \times velocity \\ = )200 \times 5 \\ = )1000kg.m.se {c}^{ - 1}$

Momentum Of Truck After Collision:-

Mass x Final velocity or m2v2:-

$m2v2 = )mass \: \times velocity \\ = )2000 \times v \\ = )2000v$

BY CONSERVATION OF MOMENTUM

$m1u1 + m2u2 = m1v1 + m2v2 \\ = )4000 + 5000 = 1000 + 2000v \\ = )9000 = 1000 + 2000v \\ = )8000 = 2000v \\ = )4m.se {c}^{ - 1}$

Hope It Helped