2. All Homework will be graded this week. All Class work will be graded. Chapter Test and Voc. Test will be on Thurs.

3. Lesson 1 What Factors Affect Motion?

4. Q. Have you ever sat in an unmoving car, when the car next to you started to move? Q. Did you feel like you were moving forward or backward? Q. When did you realize that it was the other car moving, not you?

5. Frame of Reference- what you must have in order to determine if an object is moving. Q. How do you define if an object is moving or in motion? An object is moving when its position changes. Position-location of an object in space, and it is always relative to a frame of reference. (Position Words-east, west, above, below, beside, between, etc.)

6. All forces from gravitational force, to magnetic force, to friction are pushes or pulls.

7. Forces Gravitational force- 1. Attracts two objects 2. Increases as the objects’ mass increases 3. Earth has the largest mass that directly affects us. 4. The sun has the greatest mass in our solar system. Friction 1. Force that opposes motion 2. Prevents motion or slows it down 3. Acts between two surfaces 4. Smooth surfaces=less friction 5. Rough surfaces=more friction

8. More than one force usually acts on an object. Let’s use an airplane as an example. 1. Drag (friction in gas or liquid) slows the plane 2. Thrust (forward force) is produced by the engine and works against drag 3. Lift is the force that pulls the plane into the sky 4. Gravity opposes lift and pulls the plane to the ground For the plane to fly, lift and thrust must be equal to or greater than gravitational force and drag.

9. Speed and Velocity Speed Velocity Speed-distance an object travels in a certain amount of time. Tells you how quickly or slowly an object is moving. Speed= __Distance_ Time Velocity-measure of an object’s speed in a particular direction. Velocity can be changing if the speed or direction changes, or if both changes. Velocity= Distance in a particular Time direction

10. Acceleration Acceleration-is the rate at which velocity changes over time. Therefore, any time the velocity (speed and/or direction) changes, the object is accelerating. Deceleration and acceleration are opposites.

11. Momentum Momentum-the property of motion that describes how hard it is to slow down or stop an object. Describes how an object will affect something it bumps into. Depends on mass and velocity.

12. The truck has a greater mass, so it has more momentum. (at the same speed) However, if the car is going 3x as fast, it will them have greater momentum. mass___ Momentum= velocity

15. Lesson 2 What are the Laws of Motion?

16. Sir Isaac Newton Newton- a famous scientist that lived from 1641-1727. Is famous for 1. 3 Laws of motion 2. Law of gravitation 3. Experiments with lights and prisms.

17. Newton’s First Law of Motion Inertia-the tendency of objects to resist a change in motion. Objects at rest don’t move unless a force moves them. Objects in motion don’t slow down, stop, or turn unless a force makes them do so. No acceleration can happen without a force.

18. Newton’s Second Law of Motion An object’s acceleration depends on the object’s mass and the force applied to it. The larger the force, the greater the acceleration. The less an object’s mass, the less force it till need to move it. For a force to move an object, the force must overcome other forces. Acceleration=__force___ mass

20. Newton’s 3 rd Law of Motion For every force there is an equal and opposite reaction. What goes up, must come down. When one object pushes on another, the other object pushes back on the first.

24. Lesson 3 How Do Waves Move Through Different Materials?

25. Lab p.195 (20 Minutes) LM.81

26. Sound Energy Sound is the form of energy that travels through air. It is made when something vibrates. A vibration is a back-and- forth movement of matter. There is no sound in outer space, because there is no air.

27. Some sounds are louder than others. Volume-the loudness of a sound Volume is measured in decibels (dB). The softest sound a human can hear is OdB. Sounds above 100 dB can damage a person’s ear.

28. Sound Waves Sound travels through the air as waves. Molecules of air are compressed, or squeezed together. The compressed air pushes the air next to it. This passes the compression along, like a wave on the beach.

29. Pitch and Frequency Pitch Frequency Pitch-is how high or low a sound is. Changing the length of a guitar string will alter the pitch of the sound you hear. Frequency-number of vibrations per second A sound with a high frequency has a high pitch. A sound with a low frequency has a low pitch. Small objects often vibrate at higher frequencies than large objects do.

30. Sound waves move out in all directions from an object that makes the sound. When a sound wave hits something, some or all of the energy is absorbed. Soft surfaces absorb more sound than hard surfaces. A sound that bounces off a surface is called an echo.

31. Sound Transmission Air is not the only matter that can carry sound waves. Any kind of matter can be made to vibrate and carry sound. Sound can travel through liquids (water) and solids (doors).

32. Speed of Sound The speed of sound depends on the medium through which sound is moving. Sound moves faster in warm air than in cold air. Sound travels faster in solids and liquids than it does in gases.

33. Animals and Sound People= frequency of 20,000 vibrations per sec. Bats=frequencies of 100,000 per second. Bats use echos to fly at night. Grasshoppers detect vibrations using the membrane near their leg.