(English Medium) ICSE Class 9 - CISCE Question Bank Solutions

Explain the following : 

As a ship in harbour is being unloaded, it slowly rises higher in water.

Explain the following : 

A balloon filled with hydrogen rises to a certain height and then stops rising further.

Explain the following : 

A ship submerges more as it sails from sea water to river water.

A rubber ball floats on water with its 1/3^rd volume outside water. What is the density of rubber? 

A block of wood of mass 24 kg floats on water. The volume of wood is 0.032 m³. Find: 

1. the volume of block below the surface of water,
2. the density of wood.

(Density of water = 1000 kg m⁻³)

A wooden cube of side 10 cm has mass 700 g. What part of it remains above the water surface while floating vertically on water surface? 

A piece of wax floats on brine. What fraction of its volume is immersed?

If the density of ice is 0.9 g cm^-3, then what portion of an iceberg will remain below the surface of water in sea? (Density of sea water = 1.1 g cm^-3) 

A piece of wood of uniform cross section and height 15 cm floats vertically with its height 10 cm in water and 12 cm in spirit. Find the densities of wood and spirit. 

A wooden block floats in water with two-third of its volume submerged.
(a) Calculate the density of wood. 
(b) When the same block is placed in oil, three-quarters of its volume is immersed in oil. Calculate the density of oil. 

The density of ice is 0.92 g cm^-3 and that of sea water is 1.025 g cm^-3. Find the total volume of an iceberg which floats with its volume 800 cm³ above water. 

A sinker is found to weigh 56.7 gf in water. When the sinker is tied to a cork of weight 6 gf, the combination is found to weigh 40.5 gf in water. Calculate R.D. of cork.

A solid lighter than water is found to weigh 7.5 gf in air. When tied to a sinker the combination is found to weigh .If the sinker alone weighs 72.5 gf in water, find R.D. of solid.

A hollow cylinder of copper of length 25 cm and area of cross-section 15 cm², floats in water with 3/5 of its length inside water. Calculate:
(1) apparent density of a hollow copper cylinder.
(2) wt. of cylinder.
(3) extra force required to completely submerge it in water.

A cork cut in the form of a cylinder floats in alcohol of density 0.8 gcm^-3, such that 3/4 of its length is outside alcohol. If the total length of the cylinder is 35 cm and area of cross-section 25 cm², calculate:

(1) density of cork
(2) wt. of cork
(3) extra force required to submerge it in alcohol

When a piece of ice floating in water melts, the level of water inside the glass remains same. Explain.

An inflated balloon is placed inside a big glass jar which is connected to an evacuating pump. What will you observe when the evacuating pump starts working? Give a reason for your answer.

A trawler is fully loaded in sea water to maximum capacity. What will happen to this trawler, if moved to river water? Explain your answer.

A body of mass 50 g is floting in water. What is the apparent weight of body in water? Explain your answer.

A body of mass ‘m’ is floating in a liquid of density ‘p’

what is the apparent weight of body?