3 ms·
"When ... T = 10, weight A begins to rise". No; the Tension the guy is supporting at rest is bigger than 10 (there are 2 other weights) so at T = 10 he would b
by lazyant 16y ago
"When ... T = 10, weight A begins to rise".
No; the Tension the guy is supporting at rest is bigger than 10 (there are 2 other weights) so at T = 10 he would be moving backwards. He needs to apply a bit more than the tension at rest.
(edit: this is for when all 3 weights are in the air, I see now some people see them in a floor that is not drawn)
- brlewis 16y agoThe bottom of each weight is at about the same level as the bottom of the man's feet. A floor is the natural thing to assume. Otherwise it would be difficult to get them into this configuration.
- leif 16y agoA good way to think about this is to replace the man with a fourth weight, fixed to the rope (as opposed to a pulley). Now it should be clear that the weights would not rest in that configuration unless they were supported by a floor.
- lookACamel 16y agoThere must be a floor ... or maybe the man is floating!