FREE Registration for Physics online tutoring and homework help.




Newton’s Three Laws

Newton’s Three Laws: This lecture is all about Newton’s First (inertia), Second (F=ma) and Third (action=-reaction) Laws. He builds on past discussion of vector forces, moving on to decompose forces in the x and y directions. As the class comes to an end, Professor Lewin ends with a bizarre demo involving two identical strings, one suspending a mass, the other suspending from the mass. Which one breaks when you pull on the lower string, the upper string or the lower string? Professor Lewin pulls a fast one!