Veritasium Videos seen in class What is Gravity? https://www.youtube.com/watch?v=mezkHBPLZ4A This video relates the three main ideas about gravity. They are all right. This video starts out with the most elementary ideas (ideas one and two) and then ends with Newton’s Law of Universal Gravitation – which states that all objects are attracted to all other objects. Misconceptions about Falling objects. https://www.youtube.com/watch?v=_mCC-68LyZM This video addresses why objects of similar size, but not mass, will hit the ground at the same time. Remember, that although they do hit the ground at the same time, the heavier object (the one with more mass) has a greater force than the lighter object. They hit the ground at the same time because of inertia. The heavier object has more inertia (resistance to change in motion) and so it take more force to accelerate that object at the same rate as the lighter object. This results in both objects hitting the ground at the same time. Why does the Moon orbit the Earth? https://www.youtube.com/watch?v=zN6kCa6xi9k This video address the reason behind the Moon’s orbit around the Earth. Remember there are two forces keeping the Moon in orbit – gravity and inertia. Gravity is pulling the Moon towards the Earth, while inertia keeps the Moon wanting to go in a straight line. You can demonstrate this by attaching an object to a string and swinging it around you. The object will set in motion around you as long as you swing the string (gravity) but when you let go of the string, the object will continue moving in a straight line away from you (inertia).