No problem, glad I could help!

[FeDeX_LaTeX]

Kinematics -- Vector DE

Homework Statement

The Attempt at a Solution

Here's their solution.

I'm stuck on (b). The first and second lines are fine. But how do they get from the second line to the third line? And then in the fourth line, why are they integrating from u^2 to v^2?

EDIT: Sorry for the image size.

 

[Chestermiller]

They make the substitution v² = x.

Chet

 

[FeDeX_LaTeX]

They make the substitution v² = x.

Chet

That's it?! I thought x denoted position (as a function of time)! Was losing my mind over this. Thanks.