Khan Academy Static

When two or more objects must move with the same magnitude of acceleration (like masses on strings, or boxes pushed into each other), we can treat the entire system as a single object when finding the acceleration.

9968_Masses_on_incline_system_problem.html

9964_Treating_systems_the_hard_way_.html

9965_Treating_systems_the_easy_way_.html

9966_Two_masses_hanging_from_a_pulley.html

9967_Three_box_system_problem.html