# Class 9 Science Gravitation test questions

Question 1
Define
1.  Buoyancy
2. Factor of buoyant force
3. Archimedes  Principle and its use
Question 2
Explain why
1) Pressure on ground more when man is walking than he is standing?
2) A bucket of water is lighter when in water than when it is taken out of water?
3) An iron nail floats on mercury but sink in water
4)  It is easy to walk on sand with flat shoes than with high heel shoes?
Question 3
A iron cube of side 10 c m   is kept on a horizontal table. If the density of iron is 8000 kg/m3.  Find the pressure on the portion of the table where cube is kept Take g=10m/s2

Question 4
The dimension of wooden block is 2m X .25 m X .10 m.  If relative density of wood is 0.6 calculate the mass of the block in kg
Question 5
Differentiate between density and relative density
Question 6
A 100 cm3 block has a mass of 395g. Find its relative density
Question 7
A block of wood is kept on the table top. The mass of wooden block is 5 kg and its dimension are 40 cmX20cmX10 cm. Find the pressure exerted by the wooden block on the table  if it made it lie  on the table top with its sides of dimension
1)            20 cm × 10 cm
2)            40 cm × 20 cm
Take g=9.8 m/s2