|MadSci Network: Biophysics|
The word "harder" has a lot of meanings in the physical context. If you mean that you have to apply more force vertically downward on the rope, than at a 45 degree angle, then that assumption is incorrect. The force you must apply to one end of a rope wrapped around a pulley with a weight on the other end of the rope (in order to lift it) does not depend upon the angle upon which you pull it at in reference to the pulley/ground. It might be less "harder" to pull at an angle insofar that you might be able to get a better grip on the rope at an angle, or perhaps be in a better posture to put your own weight into the downward lifting, or perhaps even just walking away with the rope in hand and not using your arms to pull it. [Moderator Note: Just to add to Gary's answer: the mechanical advantage for a fixed pulley will be 1; if you instead made it a moveable pulley, then it would be 2 (that is, you could apply less force to lift the load than the weight of the load). But the really interesting stuff happens when you combine fixed and moveable pulleys, as shown very nicely at this site. -- RJS]
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