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Gravity and Balanced Force. What is friction?. Gravity : the force that keeps things from flying off into space. Gravity pulls people and objects downward to the Earth. Take your pencil and stand up. What happens when you let go of your pencil?. Your pencil will fall to the floor.
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Gravity: the force that keeps things from flying off into space.
Take your pencil and stand up. What happens when you let go of your pencil?
Let’s watch a video about gravity. http://www.harcourtschool.com/activity/science_up_close/104/deploy/interface.html
Let’s watch another video about gravity. • http://www.youtube.com/watch?v=A5fBgmo1V3k
Here is a fun song about gravity. http://www.youtube.com/watch?v=ET47OtuZZkQ
Let’s try experimenting with gravity. Gather a few unbreakable objects you find nearby. With a partner try to toss them in the air and watch what happens. Draw a picture in your science notebook of what happens when you toss the object in the air.
We know gravity pulls people and objects downward to the ground.
But people, cars and buildings are not pulled into the ground. Also objects resting on tables do not show any signs of movement.
There must be an upward force keeping things on the surface and at rest when undisturbed by outside forces. That force is called balanced force or normal force.
Let’s watch a video where I demonstrate balanced or normal force. http://www.youtube.com/watch?v=IUl-XiPgpNY
Let’s look at another experiment. You can try this one after you watch the video. http://www.youtube.com/watch?v=de5lO5M5a3I
As a group or with a partner experiment with balanced force and gravity. Bridges can be made by laying a piece of paper between two books, two chairs or two tables.
Try bending, twisting, tearing or folding the paper to find a design that best balances force with gravity and holds the greatest number of objects.
Once your group has designed a bridge, draw a picture of it in your science notebook and record how many objects you were able to place on the bridge before gravity took over.
Today we learned about gravity. Everything that goes up must come down.
We also experimented with balance force and gravity and made bridges out of paper!
In our next lesson we will learn about inertia. Inertia: objects will not move unless force makes it move.