ALEX Lesson Plan

     

Your MA is a Force to be Reckoned With

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  This lesson provided by:  
Author:Laura Crowe
System: Auburn City
School: Auburn City Board Of Education
The event this resource created for:NASA
  General Lesson Information  
Lesson Plan ID: 34347

Title:

Your MA is a Force to be Reckoned With

Overview/Annotation:

In this lesson, students will investigate the relationship between mass, acceleration, and force as described in Newton’s Second Law of Motion.

Students will work in teams to use a wooden car and rubber bands to toss a small mass off of a car. The car, resting on rollers, will be propelled in opposite directions. Students will vary the mass that is being tossed by each car and change the number of rubber bands used to toss the mass.  Students will then measure how far the car rolls in response to the action force generated.

This lesson was created as part of the 2016 NASA STEM Standards of Practice Project, a collaboration between the Alabama State Department of Education and NASA Marshall Space Flight Center.

 Associated Standards and Objectives 
Content Standard(s):
Science
SC2015 (2015)
Grade: 8
Physical Science
9 ) Use Newton's second law to demonstrate and explain how changes in an object's motion depend on the sum of the external forces on the object and the mass of the object (e.g., billiard balls moving when hit with a cue stick).

Insight Unpacked Content
Scientific And Engineering Practices:
Constructing Explanations and Designing Solutions
Crosscutting Concepts: Stability and Change
Disciplinary Core Idea: Motion and Stability: Forces and Interactions
Evidence Of Student Attainment:
Students:
  • Demonstrate, using Newton's Second Law, how changes in an object's motion depend on the sum of the external forces on the object and the mass of the object.
  • Explain, using Newton's Second Law, how changes in an object's motion depend on the sum of the external forces on the object and the mass of the object.
Teacher Vocabulary:
  • Sir Isaac Newton
  • Newton's Second Law of Motion
  • Mass
  • Acceleration
  • Potential energy
  • Kinetic energy
  • Force
  • External force
  • Sum
  • Motion
Knowledge:
Students know:
  • The acceleration of an object is determined by the sum of the forces acting on it; if the total force on the object is not zero, its motion will change.
  • The greater the mass of the object, the greater the force needed to achieve the same change in motion.
  • For any given object, a larger force causes a larger change in motion. Force = mass x acceleration; F=ma.
Skills:
Students are able to:
  • Demonstrate Newton's second law.
  • Articulate a statement that relates a given phenomenon to a scientific idea, including Newton's second law and the motion of an object.
Understanding:
Students understand that:
  • Newton's Second Law states that changes in an object's motion depends on the sum of the external forces on the object and the mass of the object.
AMSTI Resources:
AMSTI Module:
Experimenting with Forces and Motion

NAEP Framework
NAEP Statement::
P8.16a: Forces have magnitude and direction.

NAEP Statement::
P8.16b: Forces can be added.

NAEP Statement::
P8.16c: The net force on an object is the sum of all the forces acting on the object.

NAEP Statement::
P8.16d: A nonzero net force on an object changes the object's motion; that is, the object's speed and/or direction of motion changes.

NAEP Statement::
P8.16e: A net force of zero on an object does not change the object's motion; that is, the object remains at rest or continues to move at a constant speed in a straight line.



Alabama Alternate Achievement Standards
AAS Standard:
SCI.AAS.8.9- Investigate and identify ways to change the motion of an object (e.g., change an incline's slope, change the mass of the object).


Local/National Standards:

 

Primary Learning Objective(s):

Students will be able to predict the relationship between mass and acceleration on force.

Students will be able to state Newton's second law, Force = mass x acceleration. 

Students will be able to identify real-life examples of Newton's Second Law of Motion.

Additional Learning Objective(s):

 
 Preparation Information 

Total Duration:

31 to 60 Minutes

Materials and Resources:

Computer with Internet access

Projection equipment

Newton's Car handout - 1 per team

Materials: 

  • Newton’s cars (Pre-made by teacher; see notes in Preparation section)
  • Cotton string
  • Two rubber bands (size 19)
  • Medicine bottle (may be able to get donated from pharmacy)
  • 25 straight drinking straws (not flexi)
  • Meter stick or ruler
  • Metric beam balance or scale
  • Scissors
  • Popcorn seeds, washers, pennies, marbles, paper clips, etc. (for filling the bottles)
  • Safety goggles

Technology Resources Needed:

Computer with Internet access

Projection equipment

Background/Preparation:

Background

Newton's First Law: objects in motion stay in motion; objects at rest stay at rest unless acted upon by an outside force

Newton's Second Law: Force= mass x acceleration

Newton's Third Law: For every action there is an equal and opposite reaction

Mass: the amount of matter in an object

Acceleration: change in velocity; measured in m/s2

Preparation

You will need a smooth area for the cars to roll. 

Creating Newton's Cars

Materials

  • (1) 1 X 3 x 8 inch board
  • 3 1/4 inch diameter by 2 1/2 in long dowels or Wooden Screws
  • Wood glue

1. Cut the board into 12 8" lengths. (Optional: Bevel one edge as shown on the Newton's Car handout.)

2. Drill three 1/4" holes 3/8" deep for the dowels. If using screws for posts instead of dowels, skip Step 3. 

3. Glue the dowels into the holds. If desired, bevel the upper end of the dowels with sand paper. 

Note: Dimensions of lumber are based on rough cuts. When planed, thickness and width are smaller. A 1x3" board is actually 0.75 by 2.5 inches.

  Procedures/Activities: 

Engagement (5 minutes)

Show video clip of NASA's Newton's Second Law  

1. Ask students orally, "How do you think mass affects a force?"

2. Ask students orally, "How do you think acceleration affects a force?"

Explore (30 minutes)

1. Assign roles for teams of four students. 

  • Principal Investigator: This is the spokesperson for the group and is allowed to ask the teacher questions when the group has a question.
  • Materials Manager: This person is responsible for getting all materials for the project and is the only person allowed out of their seat. This person is responsible for returning any equipment or supplies.
  • Task Manager: This person keeps the group on task.
  • Checker: This person makes sure everyone is writing down everything correctly and that everyone is following appropriate lab safety.

2. Provide teams with handout on how to set up the Newton Car and data sheet.  You just have to give them the last two pages of the handout.  The first two pages just provide background information for the teacher.

3. Clear areas for each team to set up their experiment. 

4. Provide a station where teams can fill their bottles with different materials to change their total mass. Place the popcorn seeds, washer, etc. in different bowls for easy access. The bottles do not have to be filled to the top.  However, the rubber bands should be positioned around the approximate center of mass of the bottle to get a uniform toss. 

5. Check each team to ensure they are being consistent with procedures. For instance, placing straws differently for each test would introduce a new variable into the experiment that could affect the results. 

Tip: Provide masking tape so that students can use small tape pieces to mark the positions of the straws for consistency.

Explain (10 minutes)

Ask the students orally, "How did mass affect how far the car moved?"

Ask students, "What kind of trends did you see with your graph in the lab?"

Tell the students to think a minute on their own and develop an equation to show the relationship between mass and acceleration.

To guide students in their development of the equation, have them think about how a train (which has a large mass) hitting a vehicle would have an effect on force of impact compared to a smaller car hitting the same object.  Also, ask the students to think about how one car accelerating faster than another car would have an effect on force of impact.

Pair the students with a partner, and have them compare their equations they developed to see if they are the same or different.  Then have the students share their equations orally as a group.  Compare their equations as groups. Students should be able to defend their answers orally for the equation they developed using the examples of a train vs. a smaller car on force of impact, and they should use the example of two similar cars in mass but with different velocities.

Finally, explain orally to the students that there is a relationship, and it is: Force = mass x acceleration. This will allow for students to check their answers.

Elaboration (10 minutes)

Think Pair Share

1. Have students individually come up with an example of Newton's Second Law in real-life or when they have experienced Newton's Second Law.

2. Have students share with a partner their example.

3. One person from each pair shares the group's example.  Write the list of examples on the board for the students.

4. Have students complete an exit ticket.  Students should list 3 things they learned from lesson and one thing they still need help with.  Have students also reflect on how they performed with their roles (eg: Principal Investigator, Materials Manager, Task Manager, Checker). Students should list one thing they did well as a group and one thing they can improve upon.



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  Assessment  

Assessment Strategies

Possible assessments include:

  • Question and Answer for pre-assessment of knowledge
  • Rubric to assess project
  • List of examples at end of lesson with Newton's Second Law
  • Exit Ticket

Acceleration:

Newton's second law of motion can also be demonstrated using a water rocket.  More information can be found within the NASA Rockets Educator Guide.

Intervention:

Students who need extra support should be placed in groups with teammates sensitive to the needs of that student.

The teacher may need to more closely supervise groups that contain students who are struggling with the concept


View the Special Education resources for instructional guidance in providing modifications and adaptations for students with significant cognitive disabilities who qualify for the Alabama Alternate Assessment.