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Our Solar System

Investigation 5 – Lab

Back to Investigation 5

BE PREPARED

Supplies and Equipment:

Class Materials:

1 metric ruler
1 roll of masking tape
1 m of string
flour

Group Materials:

1 ping pong ball
1 moon ball
1 50 ml beaker

Individual Materials:

1 Student Data Record

Teacher Preparation:

1. For each group, tear one 2 cm length of masking tape and cut one 20 cm length of string. Use the tape to attach the string to the ping pong ball.

2. For each group, pour flour to the 10 ml mark into the 50 ml beaker.

3. Separate the class into five cooperative groups.

Instruction:

1. Direct each student group to obtain the following necessary materials from the distribution point: one (1) ping pong ball with string, one (1) moon ball, and one (1) beaker of flour.

GET FOCUSED

During Investigation five, students will explore planetary motion by modeling an object traveling in a circular direction.

INVESTIGATE

Trial 1

During this Trial, students will experiment with a moon ball on their lab table. Students will investigate the movement of the ball when it experiences forward motion and gravity while on the table and while in the air. They will also experiment by observing the effect of gravity without forward motion. By performing this Trial, students will be led to answer the question:

How do forward motion and gravity affect the movement of a ball?

Trial 2

Students performing this Trial will investigate how forward motion and gravity affect the movement of a planet. Students will model a planet’s orbit by spinning a ping pong ball with an attached string. The string represents the force of gravity, and the forward motion is given to the ball by students’ hands as they spin it.

Students will observe the shape of the model orbit by spinning the ball in a thin layer of flour on the lab table, allowing the ball’s path to be outlined in the flour. After performing this trial, students will be able to answer the question: How do forward motion and gravity affect a planet’s orbit?

Note: To prevent spillage of flour, consider providing a large and shallow cardboard box such as a pizza box for each group. By spreading the flour in the box, the flour remains contained. However, please be advised that by using this alteration to the Lab, students will not be in as good a position to observe the path of the ball as it is released.

Trial 3

During this Trial, students will again use the ping-pong ball model of planetary orbits. This time, however, students will investigate the movement of a planet if the gravitational force that exists between the Sun and the Earth did not exist.

To do this, students will again spin the ball in the flour. This time, however, students will let go of the string attached to the ball. After observing the motion of the ball, students will answer the question:

How would a planet move without the Sun’s gravity