Question

125-kg car traveling initially with a speed of 25.0 m/s in an easterly direction crashes into the rear end of a 8,700-kg truck moving in the same direction at 20.0 m/s. The velocity of the car right after the collision is 18.0 m/s to the east. What is the velocity of the truck right after the collision

Answer 1

The velocity of truck after collision is 20.1
`(m)/(s)`

Step-by-step explanation:

Given:

Mass of car
`m_(c) = 125` kg

Initial velocity of car
`v_(i) = 25 (m)/(s)`

Mass of truck
`m_(t) = 8700` kg

Initial velocity of truck
`v_(t) = 20(m)/(s)`

Velocity of car after the collision
`v_(c) = 18 (m)/(s)`

For finding the velocity of truck after the collision,

According to the linear momentum conservation

`m_(c) v_(i) + m_(t) v_(t) = m_(c) v_(c) + m_(t) v'`

Where
`v' =` velocity of truck after the collision,

`125 * 25 + 8700 * 20 = 125 * 18 + 8700 v'`

`v' = 20.1(m)/(s)`

Therefore, the velocity of truck after collision is 20.1
`(m)/(s)`