lesson 1 | gravity and friction - weeblyhuttonscience.weebly.com/uploads/4/8/3/8/4838576/c1l1... ·...

Lesson 1 | Gravity and Friction

Student Labs and Activities Page Appropriate For:Launch Lab 8 all studentsContent Vocabulary 9 all studentsLesson Outline 10 all studentsMiniLab 12 all studentsContent Practice A 13

Content Practice B 14

School to Home 15 all studentsKey Concept Builders 16

Enrichment 20 all studentsChallenge 21

AssessmentLesson Quiz A 22

Lesson Quiz B 23

Approaching Level On Level Beyond Level English-Language Learner

Teacher evaluation will determine which activities to use or modify to meet any student’s proficiency level.

The Laws of Motion 7

Name Date Class

LESSON 1: 5 minutes

Can you make a ball move without touching it?You can make a ball move by kicking it or throwing it. Is it possible to make the ball moveeven when nothing is touching the ball?

Procedure1. Read and complete a lab safety form.

2. Roll a tennis ball across the floor.Think about what makes the ball move.

3. Toss the ball into the air. Watch as it

moves up and then falls back to yourhand.

4. Drop the ball onto the floor. Let itbounce once, and then catch it.

Think About This1. What made the ball move when you rolled, tossed, and dropped it? What made it stop?

2. Key Concept Did something that was touching the ball or not touching the ballcause it to move in each case?

Launch Lab

8 The Laws of Motion

Name Date Class

LESSON 1

Gravity and FrictionDirections: Use the clues and the terms listed below to complete the puzzle. NOTE: There is no empty square inthe puzzle between the words of two-word terms.

contact force force friction gravity mass

noncontact force significant static weight

CluesAcross

6. the amount of matter in an object

9. Gravity is an example of this kindof force.

Down

1. a force that resists the motion of twosurfaces that are touching

2. the gravitational force exerted on anobject

3. an attractive force that exists betweenall objects that have mass

4. at rest

5. important

7. a push or pull on an object by anotherobject that is touching it

8. a push or a pull

Content Vocabulary

Name Date Class

LESSON 1

Gravity and FrictionA. Types of Forces

1. A push or a pull is called a(n) .

2. A(n) is a push or a pull on an object by another objectthat is touching it.

3. A force that one object can apply to another object without touching it is

a(n) .

4. Gravity, , and electric forces are examples ofnoncontact forces.

5. Forces have and

6. An arrow can be used to show a force; the shows thestrength of the force, and the direction of the arrow shows the of the force.

7. Forces are measured in units called .

B. What is gravity?

1. is the amount of matter in an object.

2. is an attractive force that exists between all objects thathave mass.

3. Mass is often measured in .

4. According to the law of , all objects are attracted to oneanother with a gravitational force that is proportional to the mass of the objectsand the distance between them.

a. When the mass of one or both objects increases, the gravitational force between

the objects .

b. When the distance between two objects increases, the attraction between the

objects .

5. is the gravitational force exerted on an object.

a. Near Earth’s surface, an object’s weight is the gravitational force exerted on the

object by .

b. The of an object on Earth decreases significantly only

when the object moves a great distance away from Earth.

Lesson Outline

Name Date Class

Lesson Outline continued

C. Friction

1. is a force that resists the motion of two surfaces that aretouching.

2. friction prevents surfaces from sliding past each other.

3. Up to a limit, the of static friction changes to matchthe applied force.

4. friction opposes the motion of surfaces sliding pasteach other.

a. When an object is sliding, the force of sliding friction does not

; for this reason, increasing the applied force makes

a sliding object move .

b. If you stop pushing a sliding object, the object will eventually

due to sliding friction.

5. is friction between a surface and a fluid, such as airor water.

a. Fluid friction between an object and air is called .

b. Decreasing an object’s surface area by changing its shape

the object’s air resistance.

6. One reason for friction between surfaces is the , or thedips and bumps on one surface that catch on those of the other surface.

7. One reason for friction between surfaces is that atoms and molecules with

charges attract each other.

8. decrease friction by causing a slight separation betweensolid surfaces, so they don’t contact each other.

Name Date Class

LESSON 1: 10 minutes

How does friction affect motion?Friction affects the motion of an object sliding across a surface.

Procedure1. Read and complete a lab safety form.

2. Use tape to fasten sandpaper to atable. Attach a spring scale to awooden block with an eyehook in it.

3. In the Data and Observations below,record the force required to gently pullthe block at a constant speed on thesandpaper and then on the table.

Data and Observations

Analyze and Conclude1. Compare the forces required to pull the block across the two surfaces.

2. Key Concept How did reducing friction affect the motion of the block?


MiniLab

Name Date Class

LESSON 1

Gravity and FrictionDirections: On the line before each definition, write the letter of the term that matches it correctly. Each term isused only once.

1. a push or a pull on an object

2. push or pull on one object by another object

3. applied without touching

4. makes hair stand on end

5. keeps you from floating away

6. makes a compass needle point north

7. unit of mass

8. unit of force or weight

9. resists the motion of two surfaces that are

touching

10. reduces friction

A. noncontact force

B. friction

C. electric force

D. gravity

E. lubricant

F. force

G. newton

H. contact force

I. magnetic force

J. kilogram


Content Practice A

Name Date Class

LESSON 1

Gravity and FrictionDirections: Answer each question or respond to each statement on the lines provided.

1. Define the terms below.

a. force

b. contact force

c. noncontact force

2. What are three noncontact forces?

3. What are the units for mass and weight?

4. What is the difference between mass and weight?

5. Explain how the gravitational force between two objects is affected by their mass andthe distance between them.

6. What is friction?

7. What are the three kinds of friction discussed in the lesson?

Content Practice B

Name Date Class

LESSON 1

Gravity and Friction

For this activity, you will need a small object that you can slide across a surface, such as abottle cap or a coin. You will also need a ruler or a measuring tape and a pencil.

SurfaceDistance Traveled by Object (cm)

Prediction Trial 1 Trial 2 Trial 3

1. Locate four flat surfaces in or around your home that would exert different amountsof friction on a sliding object. Record the surfaces in the Surface column. Examples ofsurfaces include a carpeted floor, a tile floor, and a glass tabletop.

2. Predict how much friction each surface will exert on an object sliding across it. In thePrediction column, rank the surfaces from 1 to 4. Write 1 for the surface you expect toexert the most friction and 4 for the surface you expect to exert the least.

3. Push the object across the first surface three different times. Use the ruler to measurethe distance it slides during each trial and record each distance in the table. Try toapply the same amount of force each time. Repeat this step for each surface.

4. Which surface exerted the most friction on the object? How do you know?

5. Did you correctly predict which surface would exert the most and least friction on theobject? Explain.

School to Home

Did you know?Friction is a contact force between two surfaces that are touching. If the surfacesslide against each other with little resistance, the force of friction is weak. Only aweak force is needed to make the object move. If the surfaces slide against eachother with a strong resistance, then the force of friction is strong, and a strongerforce will be required to make the objects move.

Name Date Class

LESSON 1

Gravity and FrictionKey Concept What are some contact forces and some noncontact forces?

Directions: On the line before each motion, write C if it is caused by a contact force or N if it is caused bya noncontact force.

1. rain falling

2. papers scattered by wind

3. a baseball sailing into the outfield

4. a magnet attracting a nail

5. rocks tumbling down a mountain

6. an elevator ascending

7. an arrow flying toward a target

8. lightning striking a building

9. a brick wall collapsing

10. a meteorite hitting Earth

Directions: Answer each question on the lines provided.

11. What is a force?

12. What is a contact force?

13. What is a noncontact force?

14. What is the unit of force?


Key Concept Builder

Name Date Class

LESSON 1

Gravity and FrictionKey Concept What is the law of universal gravitation?

This diagram represents a star orbited by two planets—planet A and planet B. The star isalso orbited by a mysterious object, object X, that entered into the star’s gravitational field.

Directions: Use the diagram to answer each question or respond to each statement.

1. The gravitational force between the star and planet A is the same as the gravitationalforce between the star and planet B. Explain why this is true.

2. The gravitational force between the star and object X is equal to the forces between thestar and the two planets. From that information, what can you conclude about object X?

Directions: Answer each question on the lines provided.

3. What is gravity?

4. What happens to the gravitational attraction between two objects as the distancebetween them increases?


Key Concept Builder

Name Date Class

LESSON 1

Gravity and FrictionKey Concept What is the law of universal gravitation?

Directions: Complete this concept map by choosing terms from the word bank and writing them in the correct spaces.

effect force gravity mass newton object unit

Directions: On the line before each statement, write T if the statement is true or F if the statement is false.

8. An object that has twice as much mass as another weighs four times as much.

9. Near Earth’s surface, the weight of an object in newtons is about 10 times itsmass in kilograms.

10. The weight of an astronaut in orbit is about 90 percent of the astronaut’sweight on Earth.


Key Concept Builder

Weight

is a(n)is the

and is measured in a(n)of

called theon the

of a(n)

1.

2.

3.

4.

6.

7.

8.

Name Date Class

LESSON 1

Gravity and FrictionKey Concept How does friction affect the motion of two objects sliding past each other?

Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term isused only once.

electrical fluid lubricants microscopicmovement resistance sliding static

1. Friction is a force that opposes .

2. To push a heavy crate across a floor, you must first overcome

friction, which tends to hold it in place.

3. After overcoming that form of friction, you must push against

friction.

4. Friction between a surface and air or a liquid is called friction.

5. Air friction on a car or airplane is also called air .

6. Friction between solid surfaces is caused mostly by roughness on a(n)

scale.

7. Friction can also be caused by attraction between particles.

8. Friction between solid surfaces can be reduced with

Key Concept Builder

Name Date Class

LESSON 1

Force at a DistanceLobsters know their way home, and

researchers who studied lobster behaviorbelieve it is due to Earth’s magnetic field.

Earth’s Magnetic FieldScientists think that Earth’s magnetic

field is produced by the movement ofelectric charges in Earth’s core. The core ismostly iron and nickel; the inner core issolid because of the great pressure at thatlevel, but in the outer core, the metals areliquid because there is less pressure. AsEarth rotates, the liquid in the core flowsand electric charges move, creating themagnetic field. As the field travels outwardthrough the rest of Earth’s interior, the fieldlines extend from Earth near Antarctica andenter again near Canada.

Earth’s magnetic field acts like a giantbar magnet. It has two poles—north andsouth. When you put unlike poles together,you can feel magnetic attraction. Like polesof a bar magnet repel each other.

In the northern hemisphere, when acompass needle points north, we use it as atool to find a direction. However, becausethe north-pointing magnetism of thecompass needle can be attracted only bythe south pole of a magnet, the magneticpole in the northern hemisphere has asouth polarity. It follows that magneticnorth is at the geographic South Pole.

Going HomeResults of the lobster-behavior study

are illustrated below. Researchers movedone group of lobsters (squares) from theirhome at catch site 1 to the test sitesouthwest of their home. They movedanother group (circles) from their home atcatch site 2 to the test site that wasnortheast of their home.

The lobsters were placed in opaquecontainers and transported by boat alongcircuitous routes of up to 30 km; then they

were released at the test site. The next day,the lobsters were discovered positionedfacing the catch site and walking in thedirection indicated in the figure.

The researchers concluded that theirresults demonstrated that an invertebrateanimal is capable of true navigation basedupon Earth’s magnetic field.

Applying Critical-Thinking SkillsDirections: Answer each question.

1. Relate Look up pictures of the Aurora Borealis (Northern Lights) and the AuroraAustralis (Southern Lights). What are they? Why do they occur?

2. Interpret In which directions were the CS1 and CS2 lobsters walking on the secondday of the lobster study?


Enrichment

Name Date Class

LESSON 1

Air Resistance by DesignMany common objects in daily use today were designed to increase or decrease air

resistance. Choose one of the following activities, A or B.

A. Model1. Research the design, use, and construction of parachutes.

2. Diagram a common parachute design. Construct a full-sized model out of oldnewspaper or other scrap material. Display the model in your classroom. Perhaps it canhang from the ceiling.

3. Write a sentence or two describing the function a parachute serves for a parachutist.

B. Classify1. On separate index cards or pieces of paper, diagram your observations of the design of

20 vehicles parked or traveling in the neighborhood of your home or school.

2. Group the diagrams into three different classifications, based on their shapes. Namethe three groups.

3. Write a sentence or two describing the relationship between the shape of a vehicle andits performance.


Challenge

Name Date Class

LESSON 1

Gravity and FrictionTrue or FalseDirections: On the line before each statement, write T if the statement is true or F if the statement is false.

1. Gravity and magnetism are examples of contact forces.

2. Weight is the measure of gravitational force on an object.

3. Mass and weight are not related to each other.

4. Forces have strength and direction.

Multiple ChoiceDirections: On the line before each question or statement, write the letter of the correct answer.

5. You can reduce friction byA. increasing mass.B. removing lubricant.C. reducing surface area.

6. Which type of friction exists between a surface and moving air?A. fluid frictionB. static frictionC. sliding friction

7. Which factor is NOT involved in determining gravitational force?A. massB. speedC. distance

8. A is NOT a force.A. fallB. pullC. push


Lesson Quiz A

Name Date Class

LESSON 1

Gravity and FrictionCompletionDirections: On each line, write the term that correctly completes each sentence.

1. Gravity and magnetism are examples of forces.

2. is the measure of gravitational force on an object.

3. An object’s weight is proportional to its .

4. Forces have strength and .

Short AnswerDirections: Respond to each statement on the lines provided.

5. State two ways to reduce friction on an object.

6. Recall the three types of friction and explain how each acts on objects.

7. Assess what determines the strength of gravitational force between two objects.

8. Determine what is needed to exert a force.


Lesson Quiz B

lesson 1 | gravity and friction - weeblyhuttonscience.weebly.com/uploads/4/8/3/8/4838576/c1l1... ·...

Documents