Wait! There’s a boo-boo! I made a error in #8. I wrote down “24.8” instead of “24.2” for the speed of the goo. My bad! Sorry. The answer should be 0.321 m/s [forward] for #8 on the Momentum Pretest KEY. Wait more! #4 (a) should also be negative. The calculation is fine, I just forgot to write a negative sign in front of the 14. Sheesh!
Below is the “Crash Course” Video on Momentum and Collisions. Up to 6:10 is great, then she discusses “centre of mass” which is very interesting and important, but not part of our course.