View Single Post
Feb25-12, 06:42 PM
P: 746
I don't understand conceptually how something accelerating down weighs less. For example, the elevator example of course if you have something with a string and a weight and the acceleration of the elevator increases upward as positive, you get

T - mg - ma = 0

and for acceleration down, you get

T - mg + ma = 0

This to me doesnt make sense, because shouldnt the equations be switched around because ma is + going up and - going down??
Phys.Org News Partner Physics news on
Physicists discuss quantum pigeonhole principle
First in-situ images of void collapse in explosives
The first supercomputer simulations of 'spin?orbit' forces between neutrons and protons in an atomic nucleus