GO IN DEPTH

# Ramps 1: Let it Roll!

#### Materials

• thin, stiff, wooden or plastic board, 8-12 inches wide and 12-16 inches long
• 3 books, each 1 inch thick
• piece of carpet to place on the board
• 3-5 spherical objects of a variety of weights and sizes (ping-pong ball, marble, ball bearing, baseball)
• stopwatch or clock with second hand
• pencil and paper

### Purpose

To explore and measure the rate of spherical objects rolling down a ramp.

### Context

This lesson is the first in a two-part series on ramp building.

In Ramps 1: Let It Roll!, students explore ramps, discuss why different ramps work better than others, and practice procedures for testing designs and recording results.

In Ramps 2: Ramp Builder, students design, build, and test their own ramps.

### Motivation

It is recommended that students have experience with ramps before they attempt to build their own. You could build a ramp yourself and allow students to experiment with it, or you could focus on ramps on the school grounds. You could focus on these in the natural course of the day; for example, you could stop to discuss a wheelchair ramp on the way in from recess.

After providing students with very basic, general experiences with ramps, ask them to discuss other ramps with which they are familiar (boat ramps, highways, toys, skateboarding, etc.).

Throughout these discussions, ask questions such as:

• What do ramps help people do?
• What tasks do they perform?
• What problems would exist if we didn't have ramps?

### Development

Have students perform the following activity as a group so that they can gain experience with how ramps work. Students will first construct a simple ramp and then time how fast different objects roll down that ramp.

Introduce this activity by saying:
"Today, we will build a simple ramp like the ones we have seen here at school (if applicable) and the ones we have discussed. We will use some books and a board to make the ramp. Then, we will roll different balls down the ramp and time how fast each ball travels."

Have students follow the procedure below. You might want to choose some students to perform different tasks; for example, have some students place the books on the floor, have a student place the board on the books, have students take turns rolling objects down the ramp.

Procedure:

1. Clear a space about 10 feet long. This will be the runway.
2. Stack one or two books at one end of the runway.
3. Lean one end of the board on the books, and place the other end on the floor.
4. Have students predict which of the objects will roll slowly and which will roll quickly. Ask students to write their predictions on a sheet of paper.
5. Choose someone (preferably an older child) to take time measurements.
6. Have a student place one of the balls at the top of the ramp.
7. Ask the student to release the object without pushing it. The watch should be started at the exact same moment.
8. Tell the student who is in charge of stopwatch to stop the watch when the object reaches the bottom of the ramp.
9. Have students record the time on their papers.
10. Repeat the above steps with each object that should be tested.
11. Add one book to the pile that is supporting the ramp, and repeat the experiment. Have students predict whether the objects will roll more quickly or more slowly this time compared to the last time.
12. Now place the piece of carpet on the ramp. Repeat the steps of the experiment and again make predictions about how the object's speed will be affected.

Use the following questions to help guide students' thinking:

• Compare the time measurements of the lighter objects to those of the heavier objects. Did you expect these results?
• What happens to the rate at which the objects travel when you change the number of books supporting the ramp?
• What happens to the rate at which the objects travel when you roll them down the carpet-covered ramp?
• Refer back to the earlier discussion on the uses of ramps. Ask students to think of times when they would want objects to go down the ramp more slowly (strollers, wheelchairs, "kiddie" slides). Ask students to think of times when they would want objects to go down the ramp more quickly (slides for bigger kids, waterpark, skateboarding).

### Assessment

After each group has tested out their ramps, ask them the following questions as a way to asses their understanding of the activity:

• If you wanted to make an object go down the ramp more slowly, what would you do? Draw and label the ramp that you would build.
• If you wanted to make an object go down a ramp more quickly, what would you do? Draw and label the ramp that you would build.

### Extensions

Follow this lesson with the second lesson in the Ramps series: Ramps 2: Ramp Builder.