Question

 

A balloon filled with hydrogen has a volume of 1 m3 and its mass is 1 kg. What would be the volume of block of a very light material which it can just lift?

[Density of material of block is 91.3 kg/m3 and that of air is 1.3 kg/m3]  

Solution

Correct option is

 

For lifting Th > W. If V is the volume of balloon and v that of load and  is the density of air, then the above condition implies

         

    

  

  

                 

                 

SIMILAR QUESTIONS

Q1

A 60 kg swimmer pulls himself into a  raft moored in the meddle of a small lake. By how much does the raft sink when the swimmer climds onto it?

Q2

A clever student needs to determine the density of liquid X. She has at her disposal a spring balance and an irregularly shaped object of unknown material that is inert in air, water liquid X. In air the object weighs 2.00N. In water it weighs 1.60N. And in liquid X it weighs 1.70N. The density of liquid X is

Q3

A layer of oil deep floats on a layer of water that is 8 meets deep. The density of the oil is 300 kg/m3. A cube with a volume of 2 m3 floats at the oil-water interface with exactly half of its volume in the water. What is the density of the cube?   

Q4

A barge filled with garbage has a density of 800 kg/m3. What present of the barge’s volume is above the water line? The volume below the water line is called the draft of the ship.    

Q5

A king order for a gold crown having a mass of 2 kg. When it arrives from the goldsmith, the volume of the crown is found to be 200 cm3. What is your opinion about the crown if the density of the pure gold is ? 

Q6

 

If a room has dimensions , what is the mass of air in the room if density of air at NTP is 1.3 kg/m3?

[Density of water is 103 kg/m3 and g = 10 m/s2]

Q7

What force  does water exert on the base of a house tank of base area 1.5 m2 when it is filled with water up to a height of 1 m? [Density of water is 103 kg/m3 and g = 10 m/s2

Q8

When equal volumes of two metals are mixed together, the specific gravity of alloy is 4. When equal masses of the same two metals are mixed together, the specific gravity of the alloy is 3. Calculate the specific gravity of each metal.    

Q9

An open end wide tube is immersed vertically in mercury in such a way that a length 0.05 m extends above the mercury level. The open end of the tube is then closed and the tube is raised further by 0.43 m. Calculate the length of the air column above the mercury level in the tube.

                                                                         

Q10

A certain block weighs 15 N in air. It weighs 12 N when immersed in water. When immersed in another liquid, it weighs 13 N? Calculate the relative density of (a) the block (b) the other liquid.