Can you lift yourself standing on a wooden block using pulley mounted on block? I am new to this site. Please help me figure out this problem.
Is it possible to lift oneself like shown in schematic?
Waiting for good suggestions.
Chirag
 A: Can you pull hard enough to keep yourself from falling? That might make it a little clearer. 
Think of the forces on the pulley. What are the upward forces? Downward? 
If you pull harder, how much do the upward and downward forces change? 
A: Yes, that should work, though it looks like the person standing on the block might need a good sense of balance.
A: This is a quite usual mechanism. Only the mass relations are a bit different than usual. You are standing on the cement block (small earth) where a deviating roller is mounted and you are pulling the big earth away from you (against the gravitational force). Between both earths there is the weight-force (with actio=reactio). So, if you are strong enough to to carry your own weight and that one of the cement block;-)...'
A: First, consider the man, block and pulley as a single "object", mass M.  All of the forces between these three parts are internal to the object, and do not affect its motion.
The only force that can lift the "object" is the tension in the rope coming down from the ceiling.  If that tension is large enough and kept large enough, the object will rise.  The man can increase that tension by pulling upward on the rope.  If he can pull hard enough and keep pulling in rope, he can lift the block and himself.
Consider this slight change: the man simply ties the block around his ankle, and starts climbing the rope.
