Question

A solid sphere of iron has volume 100 cm3 and weighs 750 g-wt. Will it sink or float when placed
in water ?
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Answer 1

Given:

Sphere A: [made up of wood]

Volume =100cm³

density of sphere A=0.3gm/cm³

mass of sphere A:

m=volume x density

⇒0.3x100⇒30 gms.

So weight of Sphere A is =W=mg=30x 980=29400N

For sphere B:[ Made up of iron]

volume=100cm³

density of sphere :8.9 gm/cm³

mass=volume x density

⇒100 x 8.9⇒890 grams

weight of sphere B is =W=mg=890 x 980=872200N

Since sphere A is made up of wood, its density is less than water , it will float.,

since sphere B is made up of iron, its density is more than water it will sink.

UPTHRUST ON SPHERE A;

for sphere A to float, by laws of flotation

upthrust= weight of sphere A

∴upthrust on sphere A is 29400N

UPTHRUST ON SPHERE B;

upthrust=Volume of water displaced x density of water x g

=100x 1x 980

98000N

Hope it helps u

Answer 2

Explanation:

spehere are made of wood