In theory there is no difference in efficiency (it would be 1), but in practice I think a block and tackle would lose more force to friction in the pulleys and between the rope and pulleys.
A mechanical advantage greater than one means you can perform more work than the effort you expend. The mechanical advantage gives you more capability. A mechanical advantage of only 1 means you really do not have any advantage.
You need a velocity multiplier. A common example is a bicycle wheel.
4 (:
Science is too broad of a topic to tackle as a whole.
One moving pulley attached to the object being lifted, but one may not be enough for very heavy loads. That would depend on what lifting devices you had on hand, and how heavy the load is. If the load is say 300 lbs. and you only have one man available to do the lifting; then you would not use a simple single pulley because you would be lifting the full 300 lbs. as dead weight. If you elect to use a Gun Tackle you would gain a mechanical advantage of 2. Thus dividing the dead weight load by a factor of 2, which would mean that the man hauling on the running end of the rope would be experiencing a load of 150 lbs. On the other hand if you were to use a Luff then the M.A. is 3; thus reducing the load to 100 lbs. A Double Tackle gives you an M.A. of 4; reducing your load weight to 75 lbs. A Gyn Tackle (1 triple sheave block and 1 double sheave block) gives you an M.A. of 5; the man on the pulling end of the system is now only experiencing a pull of 60 lbs. A Threefold Purchase (2 triple sheave blocks) gets an M.A. of 6; thus 50 lbs. But for all practical purposes, you would not elect to dig out a Threefold Purchase for such a small load to be shifted. A more efficient method would be to use either a Luff or a Double tackle. Keep in mind that as you reduce the load weight on the hauling end, you increase the amount of line you have to pull through the tackle. I.e. if you use a simple pulley, for every foot you lift the off the deck, 1 foot of line passes through the pulley. Conversely, if you use a Double Tackle (Twofold Purchase) for every one foot lifted off the deck you must pull 4 feet of line through the sheaves.
No. A pulley is a simple machine. A block and tackle is a "complex" machine, because it's made of several simple machines.
The mechanical advantage is that the force applied increases but that is compensated by the fact that the rope or chain needs to be moved through a greater distance.
its a simple machine as in easy puller
To find the mechanical advantage of a simple machine divide output force by input force. (input force is the force that we exert on a machine, and output force is the force that is exerted by a machine).
Equal to the number of cords supporting the weight.
a pulley.
Block and tackle refers to a rope threaded through a series of pulleys to provide mechanical advantage, and it is used to lift heavy objects,
I know for a fact that the answer is a pulley.
block and tackle
no but a first class lever is
It has to be Trevor Pryce.
because he was the greatest Defensive Tackle of all time