We can use the principle of moments to solve this problem.
Let the weight of the plank be represented by W.
The moment of the lead weight about the balance point is given by:
Moment of lead weight = distance from balance point * lead weight
= 30cm * 0.08kg
= 2.4 kg.cm
Since the plank is balanced, the moment of the lead weight must be equal to the moment of the weight of the plank about the balance point.
So, Moment of plank weight = W * distance from balance point
W * 30cm = 2.4 kg.cm
W = 2.4 kg.cm / 30 cm
W = 0.08 kg
Therefore, the weight of the plank is 0.08kg.
A uniform plank of wood is balanced 30cm from one end when a lead of 0.08kg is hung at one end . calculate the weight of the plank
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