Question

A 1.00-kg beaker containing 2.00 kg of oil (density = 916 kg/m3) rests on a scale. A 1.50-kg block of iron is suspended from a spring scale and is completely submerged in the oil (see figure below). Find the equilibrium readings of both scales.

Answer 1

A 1.00-kg beaker containing 2.00 kg of oil (density = 916 kg/m3) rests on a scale. A 1.50-kg block of iron is suspended from a spring scale and is completely submerged in the oil (see figure below). Find the equilibrium readings of both scales.

1.00-kg--------------m

2.10 kg ---------------mo

1.50-kg------------mb

pi=7860kg/m^3

po=916 kg/m^3

FB= Vb x po x g

=mb x po x g/pi

=1.50 x916 x 9.8 /7860 = 1.713 N

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UPPER

F=mb X g -FB = 1.50 X 9.8    -1.713 N = 12.987 N

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LOWER

F=FB +(mb+m)g = 1.713 N +(2.10+ 1.00) x9.8= 32.093 N

Answer 2