Grade 9 Physics – Thrust in Fluids, Archimedes’
Principle and Flotation (2, 3 & 5 Mark Questions with
Answers + General Questions)
2 MARK QUESTIONS (WITH ANSWERS)
1. Define upthrust.
Answer: Upthrust is the upward force exerted by a fluid on a body
immersed in it.
2. What is buoyant force?
Answer: Buoyant force is the force exerted by a fluid that opposes the
weight of an object.
3. Define density.
Answer: Density is the mass per unit volume of a substance.
4. What is relative density?
Answer: Relative density is the ratio of density of a substance to density of
water.
5. Write the SI unit of density.
Answer: kg/m³
6. What is flotation?
Answer: Flotation is the ability of a body to float in a fluid.
7. Name the instrument used to measure relative density of liquids.
Answer: Hydrometer
8. What happens when upthrust equals weight?
Answer: The body floats.
Principle and Flotation (2, 3 & 5 Mark Questions with
Answers + General Questions)
2 MARK QUESTIONS (WITH ANSWERS)
1. Define upthrust.
Answer: Upthrust is the upward force exerted by a fluid on a body
immersed in it.
2. What is buoyant force?
Answer: Buoyant force is the force exerted by a fluid that opposes the
weight of an object.
3. Define density.
Answer: Density is the mass per unit volume of a substance.
4. What is relative density?
Answer: Relative density is the ratio of density of a substance to density of
water.
5. Write the SI unit of density.
Answer: kg/m³
6. What is flotation?
Answer: Flotation is the ability of a body to float in a fluid.
7. Name the instrument used to measure relative density of liquids.
Answer: Hydrometer
8. What happens when upthrust equals weight?
Answer: The body floats.
