## 4 thoughts on “2.13”

1. Trey Torno says:

By the way, you are a proverbial "saint" for uploading these videos free of charge. Thanks!

2. carolinedoesmaths says:

Could you describe why the path coordinate unit vectors are depicted right hand negative in this problem? I understand that you compensated for this using a positive A_y value but was there a particular reason?

1. tutorpaul says:

When working with path coordinates we always want normal vector to point to center of curvature for the path. Choosing the coordinates this way ensures that the normal acceleration is always positive as its equation implies.