# Physics in Everyday Life

## Physics and Me

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## Lesson Plans

Lesson Plan 1

Purpose: To determine how fast an object is moving using distance traveled and the time required.

Objectives:

- - Measure correctly using the metric system
- - Identify how the variables of distance and time are used to determine speed

Materials:

- metric tape measure
- chalk
- stopwatch
- 3 marbles
- pencil
- science notebook

Procedure:

- 1. In a gym or hallway of your school, use a metric tape measure to identify a distance 25 m from a wall. With chalk, mark a line at that point on the floor.
- 2. Kneel 2 m behind the chalk line. While your partner holds a stopwatch, roll a marble at the wall. When the marble crosses the chalk line, your partner should start the stopwatch. When the marble hits the wall, your partner should stop timing.
- 3. Roll a second and a third marble. Try to roll each of the three marbles at the same speed.
- 4. Predict how elapsed time will vary as the speed of the marble is changed. Record your prediction. Then repeat steps 2 and 3, this time trying to roll the marbles at a consistently slower speed than the first three trials.
- 5. Repeat steps 2 and 3, this time trying to roll each of the three marbles at a consistently faster speed.
- 6. For each of the trials, calculate the speed by dividing the distance the marble had to roll (25 m) by the time it took for the marble to hit the wall. Record the speed for each trial in meters per second (m/s).

Note to Teacher: This information should be recorded in the student's science notebook.

Suggested headings:

Trial Number________Distance of Roll________Elasped Time________Speed (Distance/Time

Assessment:

- - Students should be able to predict that elapsed time will vary as marble's speed changed.
- - Students should be able to accurately measure time and distance.
- - Students should be able to accurately record data.
- - Students should be able to use numbers correctly to calculate the marble's speed by dividing distance by time.

Lesson Plan 2.

Purpose: To determine if all objects fall at the same rate.

Objectives:

- - Predict, observe and record the rate at which objects of different masses fall.
- - Interpret data on a graph to determine information about time and distance for a falling object.

Materials

- heavy ball and a light ball
- spring scale and mesh bag
- science notebook

Procedure:

- 1. Using a spring scale and mesh bag, weigh each ball and record each value in your science notebook. Place both balls on the edge of a table or cabinet.
- 2. Predict which ball will hit the ground first if they both roll off the table together. Try it.
- 3. Students should record your observations in your Science Notebook. Repeat the activity several times.

Assessment:

- - Student predictions about which ball would hit the ground first should be reasonable.
- - Students should be able to interpret data to infer if objects fall at the same rate.

Lesson Plan 3

Purpose: To help students understand Newton's theory of Action and Reaction.

Objectives:

- - Construct and build a rocket
- - Identify the steps of Newton's Law of Action-Reaction

Materials:

- balloons - long, thin type
- string - 3 meters (10 feet) long
- straws
- tape
- markers
- scissors

Procedure:

- 1. Divide students into groups of 3 - 4. Students will work together to construct their rockets
- 2. Give each group a balloon, some tape, a drinking straw and a length of string at least 3 meters long.
- 3. Put the string through the straw and then tie the string at each end to something (like door knobs at opposite sides of the room). Make the string taut. This will be the guide track for the rocket.
- 4. Blow up the balloon. (each group will blow up their balloon to a different size). When the balloon is inflated hold the end closed and get a friend to tape the balloon to the straw so that the end of the balloon is pointed in the same direction as one of the ends of the straw.
- 5. Back your balloon rocket up so that the balloon end is close to one of the guide track string.
- 6. Launch your rocket by letting go of the end of the balloon. The air escaping out the end of the balloon gives the rocket a forward motion down the string.
- 7. Students will record what they observed about their rocket in their Science Notebook.

Assessment:

- - Students will be able to relate their observations to those of Newton's Law Third Law of Motion.
- - Students should determine that the amount of air in the balloon is relevant to the distance the rocket travels.
- - Students should observe that when air was released it gave the rocket a forward thrust.14

Background Information

Rockets, jet engines and space ships are all driven forward by the same principle: every action has an equal and opposite reaction. This means pushing something out of the back of a rocket will give the rocket a forward push of the same force. In the case of rockets and jet engines, the material pushed out the back are the hot expanding gases from the burning of jet or rocket fuel.

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Glossary

Acceleration - change in speed during a certain period of time.

Air Resistance - the force with which air opposes the movement of an object through it.

Deceleration - a decrease in speed. Deceleration is a type of acceleration also since it is a change in speed.

Force - a push or a pull on an object that causes a change in motion of the object

Friction - a force that occurs between surfaces that are in contact with each other.

Gravity - force on Earth which pulls all objects toward its center.

Inertia - the tendency of an object to remain at rest or to remain in motion.

Lift - the force that allows for upward motion on a flying object

Law of Conservation of Momentum - the principle that states that momentum can be transferred but cannot be lost.

Mass - the amount of matter in an object or a body.

Matter - anything that has mass and takes up space.

Metric System - a system of measure based on the number 10 and multiples of ten

Momentum - a property of a moving object calculated by multiplying the objects mass by its velocity.

Newton - (named for Sir Isaac Newton) a unit of measurement. It is the force need to accelerate a 1-kg object one meter per second per second.

Newton's First Law of Motion - objects at rest to remain at rest; objects in motion tend to stay in motion, traveling at a constant speed and in the same direction.

Newton's Second Law of Motion - an object begins to move, speeds up, slows down, comes to a stop, or changes direction only when some force acts on it.

Newton's Third law of Motion - for every action force there is an equal and opposite reaction force.

Pressure- the force exerted over a surface divided by the area.

Speed - the distance traveled divided by the length of time it took.

Velocity - the rate of change of displacement of a moving body with time.

Weight - the measure of the force of gravity on an object.