Wheelin’ It In
Students will investigate the use of the wheel and axle to move heavy objects.
Associated Curriculum Topic
Each student needs:
- Disposable containers for transportation system body, such as empty milk cartons, water bottles, boxes etc. (students can bring them from home)
- Disposable items for transportation system wheels, such as CD’s, life savers, spools of thread etc. (students can bring them from home)
- Disposable items for transportation system axles, such as pencils, straws, chopsticks etc. (Suggestion: pipe cleaners work nicely inside a straw as a way to attach the axle to the vehicle while allowing it to turn.)
- Tape, glue
For the entire class to share:
- Weights, such as marbles, small rocks etc.
- Ramp (1 ½’ x 3’ x ½’ works well for two cars)
- Stack of textbooks to adjust incline of ramp
- Spring scale
This activity demonstrates the usefulness of the wheel and axle. A wheel and axle is a simple machine made up of two circular objects of different sizes. The axle (a small wheel) is attached to the center of a larger wheel. All wheels need an axle. The wheel and axle must move together to be a simple machine. A wheel and axle helps to move loads by reducing the amount of friction between the object you’re trying to move and the surface you’re pulling it against.
A spring scale is a device used to measure how much force is required to move something. When the scale is attached to the object and used to pull the object in the direction of motion, the needle moves up and down depending on the force. The needle will line up with one of the numbers representing the force required to move the object. If you don’t have any spring scales in the classroom, they are available at Scholar’s Choice for about $7 a piece. You can also try a hardware store.
Students can work in groups to construct their vehicles. Ask them to first build their vehicle without wheels, placing a load on the vehicle (bag of marbles, weights, etc.). Then the students will measure the force required to drag the vehicle without wheels. They can record their measurement on the worksheet (provided) under the appropriate heading. Next, they will attach wheels on an axle to the bottom of their vehicle, place the same load on again, and repeat the force measurement. Students should make sure that the axle and wheels are turning properly and that they are holding the spring scale horizontally as they pull. Have them record their measurement on their worksheet under the appropriate heading.
Students can regroup as a class to discuss their results and conclusions.
As an extension of this activity, the effect of wheels could be observed when objects move down an inclined plane under the influence of gravity. Remove the wheels and observe how the vehicle moves down an inclined plane (ramp). Then observe how the same object moves with a set of wheels.
For fun, students can have races with their vehicles on the ramps after the lesson is over.
- Where do you find wheels?
- Why are wheels used?
- What shape is a wheel? Could it be any other shape? Why or why not