Question

The volume of a balloon is 1200 metre cube. It is filled with helium of density 0.18 kg

per metre cube. What load can it lift? Density of air is 1.29 kg per metre cube.
​

Answer 1

Answer:

Explanation:

Given,

V  

b

​

=1000m  

3

 

ρ  

h

​

=0.09g/L

ρ  

a

​

=1.29g/L

g=10m/s  

2

 

Upthrust force = total downward force

V  

b

​

ρ  

a

​

h=mg+ρ  

h

​

V  

b

​

g

1000×1.29×10=mg+0.09×1000×10

1290=mg+90

mg=1200kg−weight

The correct option is B.