Question 1: Define the term 'orbital radius' in the context of planets in the Solar System.

Answer: The average distance from the center of a planet to the center of the Sun.

Question 2: Explain why planets orbit the Sun in an elliptical path rather than a perfect circle.

Answer: Because of the gravitational forces and initial velocity, resulting in elliptical orbits as described by Kepler's laws.

Question 1: Calculate the orbital velocity of Earth around the Sun, given that the average distance (orbital radius) is 1.496 x 10^11 meters. Use the formula v = √(GM / r), where G = 6.674 x 10^-11 N·m²/kg² and M = 1.989 x 10^30 kg.

Answer: approximately 29,780 meters per second

Question 2: If Mars has an average orbital radius of 2.279 x 10^11 meters, calculate its orbital velocity using the same formula. Show your working.

Answer: approximately 24,077 meters per second

Question 1: Describe an experiment to demonstrate the effect of gravitational force on planetary orbits, including the variables involved and safety precautions.

Answer: An experiment could involve using a scaled model with masses and a central force to simulate gravitational attraction, varying the mass and distance to observe orbital changes. Variables include mass, distance, and velocity. Safety precautions involve handling materials carefully and ensuring no tripping hazards.

Question 1: A spacecraft traveling from Earth to Mars takes 9 months to reach Mars, which is 225 million km away. Calculate the average speed of the spacecraft in km/h. (Assume 1 month = 30 days).

Answer: approximately 1,041 km/h

Question 1: Explain how understanding planetary orbits and velocities is crucial for planning space missions and satellite deployment.

Answer: Understanding planetary orbits and velocities allows scientists to accurately calculate launch windows, fuel requirements, and trajectory planning for space missions. It is essential for satellite deployment to ensure proper orbit insertion and stability.

Question 2: Multiple Choice: Which of the following statements is true about planetary motion? A) All planets move in perfect circles. B) Kepler's first law states that planets orbit the Sun in elliptical paths. C) Orbital velocity is independent of distance from the Sun. D) Planets do not experience gravitational forces.

Answer: B