🪀 Pendulum weight and swings: the whole packet

🪀 Pendulum weight and swings · 5th–8th grade · 1 day of testing · free · 40 minutes a sitting

My days, if the fair is 14 days away

Count back from your fair day and write in each date. Fewer days than this? The jobs share days, in this order; nothing is skipped.

Dates from my teacher

• My question is due
• Testing starts
• My results table and graph are due
• My board is due

In this packet

1. 🗓️ My project plan
2. 💭 My hypothesis
3. 🧺 Change, measure, keep the same
4. 🪜 My steps
5. 📊 My results
6. 📓 My logbook
7. ✅ My conclusion
8. ✂️ Board titles to cut out
9. 🏅 The judge's questions and my certificate

If I change how many pennies hang on the string, then how many swings it makes in 30 seconds will ________________, because _____________________________________________

What I think will happen, in my own words:

4 levels × 3 tries at each = 12 tries in all. If anything you keep the same changes, you won't know which change made the difference.

What I need

• 🧵 String or yarn: about 60 cm
• 🪙 Pennies: 20
• ✏️ A pencil
• ⏱️ A stopwatch or a kitchen timer
• 🩹 Tape
• 📏 A ruler

Be safe: 👶 Small parts

1. Tape a pencil to the edge of a table so it sticks out.
2. Tape 2 pennies together into a little stack: that's the lightest weight.
3. Tape a string to the stack and hang it from the pencil, 40 cm from the pencil to the pennies.
4. Pull the pennies out to the side until the string is straight, and let go.
5. A helper times 30 seconds while you count the swings: over and back is one.
6. Write the count down, then do it two more times.
7. Tape on more pennies to make 5, and check the string is still 40 cm long.
8. Count the swings three times with 5 pennies, then with 10, then with 20.
9. Find the mean for each weight and draw a line graph.

Write each number in your results table the moment you measure it.

I changed: Pennies on the string   I measured: how many swings it makes in 30 seconds (swings)

MY GRAPH (a line graph: pennies on the string along the bottom, swings up the side)

What I noticed: ______________________________________________

Write something every day you work on it, even the days you only gather things. More days? The three-page logbook prints from peabody.kids/science-fair/templates/logbook.

My hypothesis was ☐ right ☐ partly right ☐ not right.

I know because my numbers show:

What surprised me, or what might have gone wrong (7th and up):

Next time I would test:

Idea: Change a second thing: keep 10 pennies and try strings 20, 40 and 60 cm long, then graph swings against length beside this graph.

1. What made you want to ask this question? Say something like: I wanted to know: does a heavier pendulum swing faster?
2. What did you think would happen, and why? Say something like: I thought changing how many pennies hang on the string would change how many swings it makes in 30 seconds, and I wrote down why.
3. What did you change, and what did you measure? Say something like: I changed how many pennies hang on the string (2 pennies, 5 pennies, 10 pennies, 20 pennies) and measured how many swings it makes in 30 seconds in swings.
4. What did you keep the same, and why does that matter? Say something like: I kept the same string, 40 cm long and letting go from the same distance out to the side the same, so only how many pennies hang on the string was different.
5. How many times did you test it? Say something like: 3 times at each of my 4 levels, and I found the middle number.
6. What did you find out? Show me in your numbers. Say something like: Look at my table: 2 pennies and 20 pennies gave different numbers, and here's the pattern.
7. Was your hypothesis right? How do you know? Say something like: My numbers show whether I was right, partly right or not, and I can show you where.
8. Did anything go wrong, or surprise you? Say something like: One try was odd, so I did it again and wrote it in my logbook.
9. If you did it again, what would you change or test next? Say something like: I'd change a second thing: keep 10 pennies and try strings 20, 40 and 60 cm long, then graph swings against length beside this graph.