Homemade Sciencewith Bruce Yeany

Experiments  /  Marble Tracks & Loop-the-Loop  /  Worksheets

Marble Tracks & Loop-the-Loop: printable worksheets

Choose the sheet for the learner's age. Each prints on a single page. Build the project first, then fill it in together.

Ages 5-7: Draw & tell
Name: ______________________Date: ____________

Homemade Science with Bruce Yeany · Marble Tracks & Loop-the-Loop · Ages 5-7

Loop the Loop

Roll a marble around a loop. How high must it start?

1. Guess first: will a marble from the lowest flag go all the way around?

◯ Yes◯ No

2. Draw your track. Draw the marble going around the loop.

3. Where was the marble fastest?

◯ Top of the ramp◯ Bottom of the loop◯ Top of the loop

4. To get around the loop, the marble has to start:

◯ Lower than the loop◯ Higher than the loop

5. Draw what happens when the marble starts too low.

Ages 8-10: Predict, test & record
Name: ______________________Date: ____________

Homemade Science with Bruce Yeany · Marble Tracks & Loop-the-Loop · Ages 8-10

Find the Lowest Start

Predict, test, and find the lowest start that gets a marble around the loop.

1. Height of the top of my loop: ______. My prediction for the lowest start that works: ______.

2. Start from different flags. Try each one 3 times.

Start heightHow many times out of 3 it made it aroundWhat happened

3. What is the lowest start height that worked all 3 times? How much higher is it than the top of the loop?

4. When a marble started too low, did it ever climb higher than where it started?

◯ Yes◯ No

5. What did you find out?

6. Why do you think the marble has to start higher than the top of the loop?

Ages 11-14: Explain & design your own test
Name: ______________________Date: ____________

Homemade Science with Bruce Yeany · Marble Tracks & Loop-the-Loop · Ages 11-14

Energy Around the Loop

Measure the minimum start height, compare it with theory, and explain it with energy.

1. Loop height: ______. Lowest start that worked 3 times in a row: ______. Lowest start divided by loop height: ______.

2. Using potential energy, kinetic energy and gravity, explain why starting level with the top of the loop is not enough.

3. Physics says a perfect rolling ball needs to start about 1.35 times the loop's height. Was your ratio:

◯ Lower than 1.35◯ About 1.35◯ Higher than 1.35

4. Give two reasons your foam track needs a higher start than the perfect ball.

5. Design a fair test: change ONE thing (loop size or type of ball) and find the lowest start each time.

What I changedLoop heightLowest start that workedRatio

6. In your test, what did you change, what did you measure, and what did you keep the same?

7. Where else must something go fast enough to get around a loop or curve? Give one real-world example.

Answer guide for grown-ups

Homemade Science with Bruce Yeany · Marble Tracks & Loop-the-Loop · Answer guide

Answer guide

Ages 5-7: Loop the Loop

  1. Any guess is fine; it gets tested next. (Usually no: from a low flag the marble falls off or rolls back.)
  2. Open answer: look for effort and careful observation.
  3. Bottom of the loop
  4. Higher than the loop
  5. The marble climbs partway up the loop, then falls off at the top or rolls back down.

Ages 8-10: Find the Lowest Start

  1. Open answer: look for effort and careful observation.
  2. Open answer: look for effort and careful observation.
  3. It should be higher than the top of the loop, often by several inches.
  4. No. It never climbs higher than its start, and always ends up a little lower because of friction.
  5. The marble needs to start well above the top of the loop to make it around every time.
  6. If it started level with the loop top, it would get there with no speed left and fall. It needs extra height so it is still moving fast at the top, plus a bit more for friction.

Ages 11-14: Energy Around the Loop

  1. Open answer: look for effort and careful observation.
  2. Potential energy from the start height becomes kinetic energy. Climbing to the loop top turns kinetic energy back into potential energy. Starting level with the top would leave no kinetic energy there, but the ball must still be moving fast enough at the top or gravity pulls it off the track. So it needs extra height (extra potential energy) to keep some speed at the top.
  3. Most foam tracks give a ratio higher than 1.35.
  4. Any two: friction / rolling resistance of the foam; bumps at tape joints or kinks; the loop isn't a perfect circle; the ball rides on the channel edges and spins faster, putting more energy into spin.
  5. Open answer: look for effort and careful observation.
  6. Changed: loop size (or type of ball). Measured: the lowest start height that worked 3 times. Kept the same: the ramp, the same ball (or same loop), how the ball was released, number of tries.
  7. Examples: a roller coaster loop, a skateboarder or BMX rider in a loop, a car taking a curve on a racetrack, a bucket of water swung over your head.