Question

Radius of a ball is 10.8cm. What should be the mass of the ball in order for it to float in water?

Answer 1

Given,

Radius of ball, r=10.8cm=10.8m

Density of sphere, ρ

s

Density of water, ρ

w

=1000kgm

−3

Volume of sphere, V=

3

4πr

3

=

3

4π×0.05

3

=

3

5π

×10

−4

m

3

Weight of water displaced, ρ

w

Vg=1000×(

3

5π

×10

−4

)×10=

3

5π

N

Weight of sphere + Load = weight of displaced water

ρ

s

Vg+0.1×10=ρ

w

Vg

ρ

s

=

Vg

ρ

w

Vg−1

Specific gravity,

ρ

w

ρ

s

=

ρ

w

Vg

ρ

w

Vg−1

=1−

ρ

w

Vg

1

=1−

3

5π

1

=0.81

Hence, specific gravity of sphere is 0.81

Answer 2

Answer:

ok

Explanation:

less than the liquid cointained