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Question
A 4 m long rod of negligible weight is to be balanced about a point 125 cm from one end and a load of 18 kgf is suspended at a point 60 cm from the support on the shorter arm.
- If a weight W is placed at a distance of 250 cm from the support on the longer arm to balance the rod, find W.
- If a weight 5 kgf is kept to balance the rod, find its position.
- To which class of lever does it belong?
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Solution
(a) W × CE = 18 × DC
W × 250 = 18 × 60
∴ W = `(18 xx 60)/250`
∴ W = 4.32 kgf
(b) New W = 5 kgf
Let it be placed at a distance x from C on arm CB
∴ 5 × x = 18 × 60
∴ x = `(18 xx 60)/5`
= 216 cm
(c) It belongs to class I lever.
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