Activity

# Gravity Cars

## A hands-on science lesson about gravity using toy cars.

This hands-on science lesson is designed to teach learners with visual impairments about gravity through the use of toy cars.

### Materials

• Masking tape (to mark starting and finish lines)
• Brown paper to cover floor and make a track (at least 10 feet)
• Balsa wood board (approx. 12in X 36in)
• Wood blocks or books
• Ruler, yardstick or measuring tape
• Markers
• Toy cars
• Online Timer

### Procedure

#### Essential Questions:

• What is the force that pulls the car down the ramp?
• With which ramp does the car travel the furthest?
• With which ramp does the car travel the fastest?
• If you would like a car to move slower, would you use a low ramp or a high ramp?
• If you would like a car to move faster, would you use a low ramp or a high ramp?

#### Demonstration:

1. Create a 4 inch ramp with books or blocks.
2. Ask the students to predict “What will happen if I push the car up to the top of the ramp and let go?”  (comes/goes back down the ramp)
3. Push the car up to the top of the ramp and let go (repeat and encourage observation).
4. Ask:  “Why did the car go back down the ramp, what force pulled the car back down the ramp?”  (gravity)
5. Explain:  “Today, we are going to experiment and see how far and how fast gravity can make the car move down the ramp, and across the floor.”
6. Demonstrate and Explain the setup and conditions:
• First, I will make a track for the car to travel on.  (Roll out brown paper)
• Second, I will make a ramp at one end of the track and mark “Start” at the top of the ramp.  (Create a 4 inch ramp)
• Third, I will measure 10 feet (6, 8, or 10, depending on the size of the room) and mark at the end of the track “Finish” where the car needs to move to.

#### Demonstrate and Explain Experiment:

1. One teacher, holds the car at the top of the track behind the starting line.
2. Assign an adult to give the command “ready, set, go” and start the online timer with the “GO” command.
3. Teacher with the car releases the car (without pushing) and says “STOP” when the car reaches the finish line.  Stop the timer.
4. Record the time for a 4 inch ramp on a large chart.
5. Allow each student to take a turn placing the car at the top of the ramp and releasing on the command “GO” and saying “Stop” when the car reaches the finish line.
6. Record each trial, for each student for a 4 inch ramp.
7. Raise the ramp to 6 or 8 inches and repeats steps e and f.
8. As a class, compare the times it took for the car to travel 10 feet.
• Compare the relative position of objects (under, over, above, below…)
• Describe the results of experiments that show how gravity affects objects.
• Identify forces that affect the motion of an object
• Identify objects whose motion is dependent on a force.
• Describe the motion of an object by its position.

### Variations

1. If students cannot resist the instinct to push the car, hold the car in place on the start line with a ruler or stick and ask the student to pull the stick at “GO.”
2. Instead of saying “stop” have the student hit a bell or buzzer when the car crosses the line (or have the car cross a sensor that makes a sound and/or flashes a light)
3. If students struggle with saying “stop” as the car crosses the finish line, eliminate the timer and just mark the distance the car traveled on the brown paper.
4. Choose only one variable to discuss (time or distance).

### NGSS Standards:

• 3-PS2-1. Motion and Stability: Forces and Interactions Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object.

By Selma Walsh