🔦 Flashlight distance and shadows: the whole packet

🔦 Flashlight distance and shadows · 1st–4th grade · 1 day of testing · free · 30 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 far the flashlight is from the toy, then how long the toy's shadow is on the wall 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

• 🚗 A toy car: 1 toy car
• 🔦 A flashlight
• 📏 A tape measure, or a long ruler
• 🩹 Masking tape, to mark lines

Be safe: 🙅 Never at faces

1. Stand the toy car on a table, about 30 cm from a bare wall, with its side facing the wall.
2. Stick bits of tape on the table in a line away from the car, at 20, 40, 60 and 80 cm.
3. Close the curtains and turn off the lights, so the room is dim.
4. Put the front of the flashlight on the 20 cm mark, aim it at the car and switch it on.
5. Stick a bit of tape on the wall at each end of the car's shadow.
6. Measure from one tape to the other, and write the number in your table under Try 1.
7. Move the flashlight to 40, 60 and 80 cm, and measure the shadow each time.
8. Do all four distances again for Try 2, then once more for Try 3.
9. Find the middle number for each distance and draw a line graph.

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

I changed: Flashlight distance   I measured: how long the toy's shadow is on the wall (cm)

MY GRAPH (a line graph: flashlight distance along the bottom, cm 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 the flashlight at 40 cm and move the car toward the wall in steps, and graph the shadow's length at each place.

1. What made you want to ask this question? Say something like: I wanted to know: does a shadow grow when the light comes closer?
2. What did you think would happen, and why? Say something like: I thought changing how far the flashlight is from the toy would change how long the toy's shadow is on the wall, and I wrote down why.
3. What did you change, and what did you measure? Say something like: I changed how far the flashlight is from the toy (20 cm from the toy, 40 cm from the toy, 60 cm from the toy, 80 cm from the toy) and measured how long the toy's shadow is on the wall in cm.
4. What did you keep the same, and why does that matter? Say something like: I kept the same toy car, standing in the same spot and the same distance between the car and the wall the same, so only how far the flashlight is from the toy 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: 20 cm from the toy and 80 cm from the toy 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 the flashlight at 40 cm and move the car toward the wall in steps, and graph the shadow's length at each place.