Saturday, April 21, 2018
The 6 Times Table Song (Multiplying by 6) | Silly School Songs
It is time to study Multiply by 6, by 7 and 8
Last week we started a new chapter in science. This week we will go on.
Lesson 2: What Are Forces?
VOCABULARY
Types of Forces
To move a ball, you can throw it, kick it, or hit it with a bat. Any kind of push or pull is a force. You must apply a force to make an object move. An object will keep moving until another force stops it. When you catch a moving ball, the force from your hand stops the ball.
Friction is one force that stops things or slows them down. When two objects rub together, there is friction between them. Most rough surfaces make more friction than smooth surfaces. You can slide farther on the ice than you can on dirt or grass.
Forces also make objects change directions. You apply a force to the handlebar to turn your bike. When you push one end of a seesaw down, the other end comes up.
Some forces do not even have to touch the object. A magnet can be used to push or pull objects made of iron or steel. This is called magnetic force. A magnet can pull a nail.
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MAIN IDEA AND DETAILS A magnet picks up paper clips. What force is at work?
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Ways That Forces Change Motion
Three things affect the motion of an object.
• the strength of the force
• the direction of the force
• the mass of the object
The stronger the force is, the greater the change in motion. If you toss a ball gently, it doesn’t move fast or far. If you throw a ball hard, the ball moves faster and farther. You use more force on the ball when you throw it as hard as you can.
If an object is not moving and a force pushes or pulls it, the object will move in the direction of the push or pull. When you pull up on an object, it comes up. When you push an object to the right, it moves to the right.
The smaller the mass of an object is, the easier it is to move. It takes less force to pick up a pencil than to pick up a book since a pencil has less mass.
You can add all the forces that push or pull on an object. The sum is called the net force. Suppose you and a friend push the same way on a door. The net force on the door equals your push plus your friend’s push.
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MAIN IDEA AND DETAILS Name three things that affect the motion of an object and tell what each one does.
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When equal forces act in opposite directions, they cancel each other out. The net force is zero.
Why does the waterfall back down to Earth after shooting up from the fountain?
Gravity
When you throw a ball into the air, you know that it will come
back down. Gravity is a force that pulls two objects toward each other. The
ball comes back to Earth because Earth’s gravity pulls on it.
Gravity is a very weak force between most objects. You don’t feel
the force of gravity between you and your desk. But Earth’s gravity pulls very
strongly. This is because Earth is so large.
The force of gravity depends on how much mass an object has. Weight is a measure of the force of gravity on an
object. Objects with a large mass weigh more.
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MAIN
IDEA AND DETAILS Does gravity
pull a horse or a puppy harder? How do you know?
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Tuesday, April 17, 2018
Monday, April 16, 2018
Friday, April 13, 2018
Grade 3 Math and Science H.W
April 15- April 19
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Date
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Math
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Science
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Sunday, April 15
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Multiply by 4
H.W: Book p.387-388
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Chapter 15 Force and Motion
Lesson 1: What Is Motion?
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Monday,
April 16
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Divide by 4
H.W: Book p. 393-394
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Chapter 15 Force and Motion
Lesson 1: What Is Motion?
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Tuesday,
April 17
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Problem Solving
H.W: Sheet
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Chapter 15 Force and Motion
Lesson 1: What Is Motion?
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Wednesday,
April 18
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Multiply by 0 and 1
H.W: Book p.407-408
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Chapter 15 Force and Motion
Lesson 1: What Is Motion?
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Thursday,
April 19
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Divide by 0 and 1
H.W: Book p.413-414
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Chapter 15 Force and Motion
Lesson 1: What Is Motion?
H.W : Sheet
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This week lesson is very interesting, we will learn about Motion
Chapter 15 Force and Motion
Lesson 1: What Is Motion?
VOCABULARY
Types of Motion
Suppose you are on the playground. What kinds of motion do you see? A girl throws a ball forward. It curves up and then falls down. A boy bounces a basketball. It goes up and down. Some children run fast and zigzag as they play tag. Others go back and forth on swings or up and down on seesaws. Still others go round and round on a merry-go-round.
You can observe many kinds of motion on a playground. The next time you are on a playground, think about all the ways you move.
An object can keep traveling in one direction, or it can change direction. Objects can move fast or slowly.
Every object has a position or location. A school bus stops at the same position every day, so you know where to wait for it. You know the position of the cafeteria in your school. The cafeteria’s position does not change. What is your position right now?
Motion is a change of position. To get to the cafeteria, you would need to change your position. You would need to move. When you ride a bike down the street, the bike changes position. It is in motion. If you park the bike in a bike rack, the bike is no longer changing position. It is no longer in motion.
COMPARE AND CONTRAST What is one way in which each kind of motion is different from the others? How are all kinds of motion the same?
Distance, Direction, and Time
Suppose you are on a trip with your family. You ask, "How far do we have to drive to get to the next city?" What you want to know is the distance. Distance is how far it is from one location to another.
Distance is often measured in inches, yards, or miles. Scientists use units of centimeters, meters, and kilometers. You can use a ruler to measure distances.
An important thing to know about motion is its direction. Your family’s car is going east from Chicago to New York. Your friend throws a ball up into the air.
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The greyhound is a fast runner. It can cover a long distance in a short time.
This ice skater is going very fast and travels a long distance in a short time. Her direction changes as she rounds the curves of the track.
Another important thing to know about motion is time. Time is a measure of how long it takes for an object to move. Something that moves fast covers a long distance in a short time. A fast third-grader can run a 50-meter dash in 10 seconds. A snail needs an hour to crawl the same distance!
In science, time is often measured in seconds. Other units of time include minutes, hours, days, and years.
COMPARE AND CONTRAST You are walking home from school. Your parent is driving from your home to school. How is your motion different from your parent’s?
The motion of this honey is slow. Its direction is straight down
Speed
Speed is the distance an object moves in a certain period of time. Suppose a lion could run 80 kilometers (50 miles) in one hour. You find its speed using both distance and time.
Suppose that things travel the same distance in different amounts of time. They would have different speeds. A third-grader who runs the 50-meter dash has a speed greater than a snail that travels 50 meters.
What if two objects traveled for the same amount of time but they went different distances? The object that traveled farther had a greater speed.
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Monday, April 9, 2018
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