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प्रश्न
A crowbar of length 100 cm is used to lift a load of 5 kgf. It has its fulcrum at a distance of 20 cm from the load. Calculate:
(i) the mechanical advantage of a crowbar and,
(ii) the effort applied at the other end.
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उत्तर
Given: L = 5 kgf, Load arm = 20 cm, Effort arm = 100 – 20 = 80 cm.
(Since the crowbar is the lever of first order with the fulcrum in between the load and the effort).
(i) Mechanical advantage =`("Effort arm")/("Load arm")=80/20=4`
(ii) M.A. =`"Load(L)"/"Effort(E)"`
∴ Effort =`"Load(L)"/"M.A."=5/4`
= 1.25 kgf.
संबंधित प्रश्न
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A man uses a crowbar of length 1.5 m to raise a load of 75 kgf by putting a sharp edge below the bar at a distance 1 m from his hand.
- Draw a diagram of the arrangement showing the fulcrum (F), load (L) and effort (E) with their directions.
- State the kind of lever.
- Calculate:
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- effort arm,
- mechanical advantage and
- the effort needed.
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- State the principle of moments as applied to the above lever.
- Which class of lever is this? Give an example of this class of lever.
- If FA = 100 cm, AB = 90 cm, calculate the minimum effort required to lift the load.
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