2200 kg semi truck driving down the highway has lost control. The truck rolls across the median and into oncoming traffic. The truck collides with a 2000 kg car that is traveling north at 45 m/s. The two vehicles stick together creating a single wreck that travels south at 15 m/s. what was the initial speed and direction of the semi truck?

The semi truck travels at an initial speed of 69.545 meters per second downwards.

Explanation:

In this exercise we see a case of an entirely inellastic collision between the semi truck and the car, which can be described by the following equation derived from Principle of Linear Momentum Conservation: (We assume that velocity oriented northwards is positive)

(1)

Where:

, - Masses of the semi truck and the car, measured in kilograms.

, - Initial velocities of the semi truck and the car, measured in meters per second.

- Final speed of the system after collision, measured in meters per second.

If we know that , , and , then the initial velocity of the semi truck is:

The semi truck travels at an initial speed of 69.545 meters per second downwards.

answer and explanation;