Question 2 Which planet is moving faster? (If equal, mark C.) A B Explanation The correct anawer is B. moment depicted in the picture, Planet Bis ciccor sun, therefore orbite it at a greater velocity The gravitational force between two objects is calculated by: Fg (m: X ma x G)/ Where: FgGravitational Force, mi Mass of Body 1, no Maus of Body 2, G Gravity Constant, d Distance Between the two Bodies You need not remember this formula; however, remember that gravitational force a inversely proportional to the distance squared (The larger the distance, the distance squared (The larger the dist farct Remember the physical principle: The closer an orbiting object is to the main object (the abject orbited), the faster it travels. Note: The rule alse applies for planets with a circular orbit in that case, the planet maintains a constant velocity. V1 In that example V1 V2. Question 3 Which pendulum will swing faster (If equal, mark C.) 5kg A 1kg B Explanation The correct answer is A. Pendulum A has a shorter string; therefore, it will swing faster. Intuitively, the shorter pendulum has less distance to travel in every cycle and, therefore, will move faster. The mass of the bob is irrelevant, since the pendulum is affected by gravity, which applies the same acceleration on each body, regardless of its mass. Both bobs accelerate the same; therefore, their mass does not affect the pendulum's movement. Remember the physical principle: The only thing that determines how fast a pendulum will swing is the length of its string.