LabLearner—The Science of Learning
LabLearner—The Science of Learning

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Earth’s Forces

Investigation 2 – Lab

 

 

 

 

 

 

 

Back to Investigation 2

BE PREPARED

 

Group materials:
  • 1 triple beam balance
  • 1 stick of modeling clay
  • 1 stopwatch
  • 1 meter ruler
  • 1 calculator
Individual materials: 
  • 1 Student Data Record

Teacher Preparation

  1. Place all materials at the distribution center.
  2. Divide the class into five (5) cooperative groups.

Instruction

  1. Direct each student group to obtain the following necessary materials from the distribution point: one (1) triple beam balance, one (1) stick of modeling clay, one (1) stopwatch, one (1) meter ruler, and one (1) calculator.

GET FOCUSED

Students will performances that measure the time it takes for an object to fall to the floor from specific heights (distances).

As students perform their lab experiments, they should keep the following questions in mind:

      • How does gravity cause acceleration?
      • Can acceleration due to gravity be measured?

INVESTIGATE

Trial 1

In Trial 1, students will measure the time it takes for a modeling clay ball to fall 50, 100 and 150 cm. Students will create a ball from modeling clay and will find its mass. Then, students will drop the ball three times from each of three different heights. Students will record the time it takes for the ball to hit the floor.

         a. If necessary remind students of the steps in the Procedural Tool, Triple Beam Balance Equilibration and Use.

        b. If necessary remind students of the steps in the Procedural Tool, Meter Stick Use and Operation. 

        c. If necessary remind students of the steps in the Procedural Tool, Stopwatch/Timer Use and Operation.

        Note: It can be difficult to accurately use the stopwatch to time such a quick event. Students may wish to practice starting and stopping the stopwatch to coincide with the ball dropping, before collecting data. Student answers should be close to the sample data provided.

         

        Trial 2

        Trial 2 is designed to provide students with an opportunity to explore the rate of acceleration due to gravity of a larger object. Thus, while height is varied in the same way as in Trial 1, now the additional variable of mass is introduced. In Trial 2, students will measure the time it takes for a larger modeling clay ball to fall 50, 100, and 150 cm. Students are directed to make a modeling clay ball approximately twice the mass of the first ball. The data from this Trial will be used to show that acceleration due to gravity is constant even though mass changes.

        KEYS

        CLEAN UP

        Let students know your expectations for clean-up. Ask them to clean up.