Academic journal article The Science Teacher

# Try This TOPS Idea!

Academic journal article The Science Teacher

# Try This TOPS Idea!

## Article excerpt

pendulum math

... adapted from PENDULUMS #01 by TOPS Learning Systems

1. Make three thread-and-washer pendulums with these Lengths

[ILLUSTRATION OMITTED]

2. Count Time in seconds for each pendulum to make one cycle (back and forth):

[ILLUSTRATION OMITTED]

3. Show that L = 25 [T.sup.2]. More precisely, L = (g/4[[pi].sup.2])[T.sup.2] = 24.8[T.sup.2]

[ILLUSTRATION OMITTED]

4. Make a pendulum that swings with a period of 4 seconds per cycle. Swing it from a high place!

OBJECTIVE

To relate the length of a pendulum to its period. To appreciate the predictive power of mathematics.

LAB NOTES

Copy the activity for each student or lab team.

Step 3. The constant g stands for the acceleration of gravity, which is equal to 980 cm/[sec.sup.2] on Earth.

2. [T.sub.1] = 1 s/c

[T.sub.2] = 2 s/c

[T.sub.3] = 3 s/c

3. This equation holds for all three pendulums:

[L.sub.1] = 25[(1).sup.2] = 25 cm

[L.sub.2] = 25[(2).sup.2] = 100 cm

[L.sub.3] = 25[(3).sup.2] = 225 cm

4. [L.sub.4] = 25[(4).sup.2] = 400 cm

MATERIALS

EVALUATION