What Is the Speed of Trucks After a Perfectly Inelastic Collision?

[jake40208]

Homework Statement

Two trucks with same masses are moving toward each other along a straight line with speeds of 50 mi/hr and 60 mi/hr. What is the speed of the combined trucks after completely inelastic collision?

Homework Equations

P$$_{}1$$+P$$_{}2$$= (2M) V$$_{}f$$

The Attempt at a Solution

Given the trucks we can assign a random mass. To make it easy Mass = 1. So 60+50= 2V$$_{}f$$ Solve it and you get 55 mi/hr. Is this correct?

 

[zack_21]

Think of the trucks as two vectors going the opposite direction. One with a magnitude of 50 mph and one with a magnitude of 60 mph. Take the sum of these two vectors.