What We Learned

These are paragraphs about what we learned by doing this unit.

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We learned many new things by doing these activities. We learned that force means a push or a pull on an object. We also learned all about Sir Isaac Newton and all about his laws of motion. We also learned the mass is measured by how much matter makes up an object.

We learned many new things about friction like friction reduces movement and is caused when two surfaces rub together. Some things that are used to reduce friction are grease, oil, and soft waxes. Another thing we learned is that friction is really important for cars so they can slow down and air can also provide friction.

We also lerned many new things about momentum and compression by doing the collisions activity. We learned that scientists combined mass and speed into one word, momentum. If two objects have the same mass, but one is going faster, than it has more momentum so when the collide, the object with less momentum will go in the other direction while the other object will go slower. This is one of Newton's laws.

Some other things that we learned is that magnets are pieces of material that usually have iron in them that attract or repel other pieces of iron with what we call magnetic force. We also learned that opposites attract in magnets. We learned that the Earth is one giant magnet.  Magnets are made out of iron, cobalt, or nickel. a really interesting thing we learned is that the ancient Chinese were the first people to use lodestones as compasses to guide their ships to their destinations.

We also learned a number of new things about gravity. Like gravity is the name we give to the force that pulls everything towards one another. This force can cause a book to fall to the ground when it is pushed over the edge of a table and a ball to roll down a hill. The size of the force depends on the mass of the object doing the pulling. The earth pulls you down with  certain amount of force. This is force is called your weight. If you went to the moon your weight would change, but your mass will stay the same. The moon has much less mass than the earth so its gravitational pull is weaker. This is why your weight will change.

We also learned about surface tension. The slun across the top of a liquid is called surface tension. Pond scum animals can even live on surface tension. In this activity we also learned about adhesion and cohesion. Adhesion is when two different substances attract and cohesion is when two of the same substances attract. Adhesive and cohesive forces are in conflict--> Adhesive is stronger and cohesive is weaker. Glass pulling at a substance creates the meniscus. We learned that the molecules of two substances attract to eachother, the create surface tension.

Lastly, we learned a lot about speed. Like speed is the measure of the distance travelled in a certain time. And acceleration is the increasing in speed. If a car was going 200kmph then it is going 200km in one hour. This is how speed is measured. We learned that maximum speed is the fastest speed the vehicle reached and average speed is the average speed it goes in a certain time.