Question 1: Density is a measure of how much mass is contained in a given volume of a substance. It is calculated using the formula: Density = Mass / Volume. The SI units for density are kilograms per cubic metre (kg/m³).

Answer: Density is mass per unit volume, calculated as Density = Mass / Volume, with units of kg/m³.

Question 1: Define density in your own words.

Answer: Density is the mass of a substance per unit volume of that substance.

Question 2: Explain why materials with higher densities feel heavier than those with lower densities of the same size.

Answer: Materials with higher densities have more mass packed into the same volume, making them feel heavier.

Question 1: A block of aluminium has a mass of 2.7 kg and a volume of 0.001 m³. Calculate its density in kg/m³.

Answer: Density = 2.7 kg / 0.001 m³ = 2700 kg/m³

Question 2: A piece of wood has a mass of 0.5 kg and a volume of 0.0004 m³. What is its density?

Answer: Density = 0.5 kg / 0.0004 m³ = 1250 kg/m³

Question 1: Describe a simple experimental method to measure the density of a solid object.

Answer: Measure the mass using a balance, determine the volume by water displacement or geometric calculation, then divide mass by volume.

Question 2: List two safety precautions to consider when performing density experiments involving liquids.

Answer: Wear safety goggles and handle liquids carefully to avoid spills or splashes.

Question 1: A scientist measures a metal block's mass as 5 kg and its volume as 0.002 m³. Another similar block has a mass of 7 kg and volume of 0.0028 m³. Which block has a higher density?

Answer: Calculate both densities: First block = 5 / 0.002 = 2500 kg/m³; second block = 7 / 0.0028 ≈ 2500 kg/m³. Both have similar densities.

Question 2: A cylinder of iron has a mass of 8 kg and a volume of 0.005 m³. Explain how increasing the volume while keeping the mass constant affects the density.

Answer: Increasing volume while keeping mass constant decreases the density because density = mass / volume.

Question 1: Explain how knowing the density of materials is important in the shipping industry.

Answer: It helps determine the weight and volume of goods, ensuring safe and cost-effective transportation.

Question 2: Describe how the concept of density is utilised in designing submarines.

Answer: Submarines control their buoyancy by adjusting their overall density. They take in or expel water in ballast tanks to increase or decrease density, allowing them to sink or float as needed.