Gravity is a force that pulls on every object on Earth. Have you ever wondered if the pull is always the same for every single thing? If you drop a penny and pen from the same height, will they hit the ground the same time? What about a piece of paper and a pen; can you guess what will happen?
First make a ramp. You can use a binder or tilt a small desk by putting books under two of the legs. Make sure the ramp is tilted just a little bit so the marbles will roll slowly. The smoother surface, the better!
Take two marbles, a big one and a small one. Line them up evenly at the top of the ramp.
Have you ever noticed the force of a magnet? If you put two magnets next to each other, they will either push or pull on one another. The push or pull is the force of magnetism. Gravity is a force too, it makes all things attract each other. The bigger the object, the stronger the force is. Try slowly pulling two magnets apart. What do you feel?
"Common sense suggests that heavy objects are pulled toward the Earth with greater force than lighter objects. That is why they feel "heavier"; they are pulling harder against our hands as they try to fall to Earth. Does this mean that a heavy object will fall faster than a lighter object?"
Think about this statement and write a prediction in your science journal, based on your prior experiences. How could you figure the outcome after writing your prediction? How is gravity related to objects feeling heavier or lighter? (You may look at collected information in your science journal for help)