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Grade 11Mechanics

A wooden block of volume 1000 cm3 is suspended from a spring balance. It's weight is 12N in air. It is suspended in water such that half of the block is below the surface water. The reading of spring balance is

Profile image of Tejas patange
7 Years agoGrade 11
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1 Answer

Profile image of Arun
7 Years ago

Volume of the wooden block=1000cm3 =0.001 m3

Weight=Mg=12N

When half the ball is in water (density of water is 1 kg/m3), it experiences an upthrust due to half weight submerged apart from the weight force. 

Immersed volume=500cm3 =0.0005 m3

Upthrust=mass of the water displaced X g= (density of water) X (volume) X (g)

 =(1) X (0.0005) X (10)=0.005 N

Net force on the block now is: downward weight - upthrust=12-0.005=11.995N