In this experiment students prop a table or desk so that it slants and then set up a ramp perpendicularly. When a marble is rolled down this ramp it gains horizontal speed and when it rolls onto the slanted table, it gains vertical acceleration. Combining these two motions results in the classic parabolic curve of projectile motion. Kids can clearly track its motion and see its shape. Continually rolling the ball down the ramp demonstrates the repeatability of the experiment.
Students can independently adjust the horizontal and vertical speeds to show how each affects the resulting parabolic path and begin to understand that the shape of falling objects is due to constant horizontal speed combined with accelerating vertical speed.
Concepts Addressed
- All objects fall at the same rate.
- Horizontal speed has no affect on vertical speed/falling.
- Projectiles always fall with a parabolic motion.
Materials Needed per setup: grooved ruler, marble or ball bearing, blank newsprint, dish of water.
Prep Needed Gather supplies
Teaching Time 20-30 min
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