Question 1: Define gravity and explain how it affects objects on Earth.

Answer: Gravity is a force of attraction between masses. It causes objects on Earth to experience a pull towards the centre of the planet, giving them weight.

Question 2: Describe the mechanism of Newton's law of universal gravitation and its relevance to environmental science.

Answer: Newton's law states that every mass attracts every other mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between them. This explains planetary orbits and the gravitational pull affecting ecosystems.

Question 1: Calculate the weight of a 50 kg environmental scientist standing on Earth. (Use g = 9.8 m/s²)

Answer: Weight = mass × gravitational acceleration = 50 kg × 9.8 m/s² = 490 N

Question 2: A satellite orbits 400 km above Earth's surface. Calculate the gravitational force between Earth (mass = 5.97 × 10²⁴ kg) and the satellite (mass = 1000 kg). (Use G = 6.674 × 10⁻¹¹ N·m²/kg²)

Answer: First, convert altitude to meters: 400 km = 400,000 m. Distance r = Earth's radius + altitude = 6,371,000 m + 400,000 m = 6,771,000 m. Using F = G × (m₁ × m₂) / r²: F = 6.674×10⁻¹¹ × (5.97×10²⁴ × 1000) / (6.771×10⁶)² ≈ 8.68 N

Question 1: Design a simple experiment to demonstrate how gravity affects water flow in a small-scale ecological model. Include the key variables and safety precautions.

Answer: Students can set up a sloped channel with water to observe flow rate changes at different angles. Variables include slope angle and water volume. Precautions: ensure secure setup to prevent spills, handle water carefully, and avoid electrical hazards.

Question 1: An environmental report states that a 10 kg mass of sulphur is stored at a site 100 meters above sea level. Calculate the gravitational potential energy stored in the sulphur, using g = 9.8 m/s². How does this energy relate to environmental safety considerations?

Answer: Potential energy = mass × g × height = 10 kg × 9.8 m/s² × 100 m = 9800 Joules. This energy represents the potential for environmental risk if released, such as in a spill or fire.

Question 1: Explain why objects fall at the same rate regardless of their mass, and discuss how this principle is important in environmental science.

Answer: Objects fall at the same rate because the acceleration due to gravity is independent of mass when air resistance is negligible. This principle is important in environmental science for understanding natural phenomena like erosion, sediment transport, and the design of environmental monitoring equipment.

Question 1: Describe how gravity influences the movement of water in groundwater systems and why understanding this is crucial for environmental management.

Answer: Gravity causes groundwater to flow from higher elevations to lower areas, influencing aquifer recharge and pollutant spread. Understanding this helps in sustainable water management and contamination control.

Question 2: Discuss the role of gravity in the design of environmentally friendly infrastructure, such as waste disposal or water drainage systems.

Answer: Gravity drives waste and water to designated treatment or disposal sites with minimal energy use, reducing environmental impact. Proper design utilises gravity to ensure effective flow and environmental safety.