So, we're learning about forces and newton's laws in class, and my professor zips through the material without really explaining anything. I'm having the most trouble understanding f_net=ma (specifically, how that can be used in a free body diagram) and how third-law pairs fit into a free body diagram, and I was wondering what sources you've used to get a better understanding of these things. I'm a very visual/auditory learner, so videos are the best, but any online materials that I can easily access would be great. Any worksheets w/answers and stuff using newton's laws in calculations would be great, too. Thank you in advance!