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Science - 3rd Grade
Standard 4 Objective 1
In this activity, students will experience gravity just like Galileo did during his experiments.
Gravity is an invisible force that pulls together any two objects. It pulls us down toward our planet, Earth, and holds us connected to it. To prevent confusion in students who may think, based on this definition, that gravity is the same as magnetic forces, the force of gravity is presented as the force that pulls objects on or near Earth toward its surface.
In this activity, students will experience gravity just like Galileo did during his experiments. For background purposes, it should be noted that there is no concrete evidence that Galileo successfully performed this experiment. Because of air resistance, the likelihood of the musket ball and the cannon ball actually landing at the same time is doubtful. However, through many other additional experiments with controlled processes, Galileo is considered the scientist who first understood this physical force.
Gravity pulls on all objects, no matter what their mass, with equal acceleration towards Earth. That is why an apple falls from a tree, or why rain falls from the sky. Ignoring friction or air resistance, any two objects will reach the ground at the same time if they are dropped from the same height and at the same time. In this activity, experiments will demonstrate that the force of gravity on Earth is the same for all objects.
It is also important to demonstrate and explain that a baseball and a piece of paper will not hit the ground at the same time because of air resistance. As objects move through air, friction slows the objects. The more surface area an object has, the more air resistance it will have. This might be easier to visualize if you tell students that a baseball and a wadded up piece of paper will fall at the same time.
1. Use a science process and thinking skills
2. Manifest scientific attitudes and interests
3. Understand science concepts and principles
4. Communicate effectively using science language and reasoning
Pre-Assessment/Invitation to Learn
Homework & Family Connections