SHORT ANSWER QUESTIONS
Q1. Define density of a substance.
Density is the mass of a substance per unit volume.
Density = Mass / Volume
Density = Mass / Volume
Q2. Name the SI unit of density and convert it to g cm⁻³.
SI unit = kg m⁻³
1 kg m⁻³ = 0.001 g cm⁻³
1 kg m⁻³ = 0.001 g cm⁻³
Q3. What does density of brass = 8.4 g cm⁻³ mean?
It means 1 cm³ of brass has a mass of 8.4 g.
Q4. Arrange the following in increasing order of density: Iron, Cork, Brass, Water, Mercury.
Cork < Water < Iron < Brass < Mercury
Q5. How does the density of a liquid vary with temperature?
Density decreases with increase in temperature.
Q6. Which quantity changes when a liquid is heated: mass, volume or density?
Volume and density change. Mass remains constant.
Q7. Define relative density.
Relative density is the ratio of density of a substance to the density of water at 4°C.
Q8. What is the unit of relative density?
Relative density has no unit (dimensionless).
Q9. Explain the statement: relative density of aluminium is 2.7.
It means aluminium is 2.7 times denser than water.
Q10. State the law of floatation.
A floating body displaces a liquid equal to its own weight.
Q11. How is weight related to buoyant force for a floating body?
For a floating body, weight = buoyant force.
