Motion Force Teacher Guide - Newton's Second Law of Motion

Newton's Second Law of Motion

Time Required

2 CLASS PERIODS

Objectives

Students will investigate Newton’s Second Law of Motion by completing a lab.

Materials

FOR THE STUDENT

FOR EACH GROUP OR PAIR

Computer and Internet accessMeterstickStopwatchDynamic cartMasking tapeFlat surface, such as a table or deskForce meterSet of six 100g masses

Preparation

Gather materials for the lab and make copies of the Lab Sheets. Use a balance to find the mass, in kilograms, of one of the dynamic carts. Students will need this information for the lab.

GAME PLAY!

Have students play Motion Force with their partners for approximately 30 minutes. Ask students to think about what they have learned about forces and motion by playing the game.

Pause and Think

Circulate as students play and ask them some questions as you circulate. Let students know that they will encounter similar questions in the Game Discussion.

  • You add mass to your spacecraft when you pick up Fuzzies. What effect does adding mass have on the motion of the spacecraft?
  • What challenges have you had to overcome in the game?
  • Ask students to create a list of strategies they have learned by playing the game. The list should be written for a student just learning the game. Tell students to be sure to suggest ways of maximizing points earned.

Game Discusson

Have students complete the discussion questions below, which also appear in the Student Guide. Students should have begun contemplating these questions during Pause and Think. Ask students to share their responses to the questions as part of a class discussion.

  • How are you able to use forces to steer your spacecraft? Have you changed its mass? If so, how did this affect the motion of the spacecraft?
  • Did you learn any new strategies as you played the game this time? If so, what are they?

Lab: Force, Mass, and Acceleration

Distribute the Lab Sheets and have students read the introduction and materials list. As they are reading, distribute the materials for the lab. Review the procedure and address questions as needed. Tell students the mass of the dynamic cart that you measured during the preparation. You may want to set up the dynamic cart with the force meter attached so students can see how to set up the experiment.

Once students have completed the lab, discuss their results by reviewing the lab sheets as a class, focusing on the Analysis questions 1 and 2:

  • Describe the relationship between force and acceleration.
    Sample response: As force increases, acceleration increases.
  • Describe the relationship between mass and acceleration.
    Sample response: As mass increases, acceleration decreases.

By the end of the lab, students should understand the relationship among force, mass, and acceleration, and how this relates to Newton’s Second Law of Motion: The acceleration of an object by a force is inversely proportional to the mass of the object and directly proportional to the force. Write the equation on the board to reinforce the relationship among force, mass, and acceleration:

F = m*a

Exit Slip

Have students complete the Exit Slip activity in the Student Guide and submit the activity before leaving the classroom. Review the student responses before the next lesson.