Same chapter3 marksDifficulty: Medium
Why does a class III lever always have a mechanical advantage less than one, and why is it still useful?
Machines
3 marksDifficulty: Medium
State the velocity ratio of a single fixed pulley and of a single movable pulley, and give one use of each.
Original Khojo Papers practice question — not from a past board paper.
Answer
A single fixed pulley has a velocity ratio of 1 and is used to change the direction of the effort, so that a load can be raised by pulling downwards. A single movable pulley has a velocity ratio of 2 and is used to lift a load with an effort about half the load.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The fixed pulley gives no gain in force; its whole value is convenience of direction.
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