Steep and Steeper

Materials

large marbles, small balls, or cardboard tubes for rolling (toilet paper or paper towel rolls)
a number of identical ramps (cardboard, foam core, or wood—18” to 24”)
wooden building blocks (standard size) for propping up the ramps
craft sticks or other objects for marking the distance the objects roll
chalk or masking tape (for marking distance)
camera or video camera

Key Science Concepts

Rolling and sliding objects move faster and farther down steeper inclines.

Vocabulary

Encourage children to use words such as incline, slope, slide, roll, steep, steeper, steepest, fast, faster, fastest, slow, slower, slowest, and farther, as well as science process words such as observe, compare, same, different, change, and predict.

Directions

Note: Because you will be measuring the distance the ball or tube rolls, you will want to have enough space in front of the ramp for the rolling object to stop on its own. If you can build your ramps in a hallway or somewhere else with a long roll-out space, use balls, which will roll far and work well with this exploration. If you have limited space, use paper towel tubes because they don’t roll as far as balls.

With the children, build a ramp propped up with two blocks. Place a marble, ball, or tube at the top of the ramp and let it roll down. Mark where it stops.
Build a second ramp propped up on four blocks next to the ﬁrst ramp. Ask children how the two ramps are different. Have them predict how far a ball sent down the steeper ramp will travel. Do they think that it will go as far as the previous ball did? Do they think that it will go farther? Why do they think so? Then send identical balls down the two ramps at the same time and mark how far each ball rolls.
Continue to build ramps of increasing steepness by propping them up on an increasing number of blocks. Each time, have children predict how far the ball or tube will roll. Try it out and mark the distance using chalk or masking tape.

Reflect and Share

Gather children back together to share their experiences and discoveries. Ask:

What did you notice about how the balls or tubes rolled down the different ramps?
What did you do to get the balls (or tubes) to roll faster and farther?
What did you do to get the balls (or tubes) to roll slower and less far?

Extension

Challenge children to create an incline that will get the ball (or tube) to roll to a certain point on the ﬂoor or to roll into an open box or cup placed on its side at a speciﬁc spot.