Physics
Ramesh went for fishing with his fishing rod. Identify the class of lever for a fishing rod. If a fish exerts a load of 10 N and the distance between fulcrum and fish is 1.5 m, and the effort applied is 0.5 m from the fulcrum, what is the force required by the fisher to pull the fish?
Machines
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Answer
A fishing rod is an example of a Class III lever.
Here,
Fulcrum : at the handle (where the rod pivots)
Effort : applied by the fisher's hand along the rod
Load : the fish at the end of the rod
In Class III levers : Fulcrum — Effort — Load
The principle of moments states that —
Moment of the load about the fulcrum = Moment of the effort about the fulcrum
∴ Effort × Effort Arm = Load × Load Arm ………. (i)
Given :
Load (L) = 10 N
Load arm (distance between fulcrum and fish) = 1.5 m
Effort arm (distance between fulcrum and applied effort) = 0.5 m
From (i)
Effort x 0.5 = 10 x 1.5
⇒ Effort = = 30 N
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