# Lesson - Paperclip Pendulums ### Standards

Title: Paperclip Pendulums
Duration: 45 Minutes

### Standards

Science – SC.6.P.11.1
Explore the Law of Conservation of Energy by differentiating between potential and kinetic energy. Identify situations where kinetic energy is transformed into potential energy and vice versa.

### Hypothesis

• How many swings will the pendulum swing per second/per minute?
• If I add more weight to the pendulum, then it will___________.
• If the pendulum changes its angle, then it will _____________.
• If I make the string shorter/ longer, then __________________.

### Vocabulary

Pendulum • Frequency • Potential Energy • Kinetic • Energy Conservation • Law of Conservation of Energy • Vibration • Speed

### Essential Question

Can you show the law of conservation of energy?

### Background Information

Pendulums swing back and forth in a regular pattern.  Each back and forth movement is called a vibration. The time it takes for one vibration is called a period. The Law of Conservation of Energy states that energy cannot be created or destroyed.  In fact, it states that energy can only change its form to another.  A good example would be converting friction to kinetic or kinetic to thermal. Something we may be familiar with is throwing a ball in the air and how  everything that goes up comes down.

When Einstein, the famous scientist, came up with the formula E=mc2; it confused many with its mass-energy equation. However; the formula actually states that mass can be converted to energy and vice versa. In reality it demonstrates that mass and energy are actually different forms of the same thing.

### Guided Questions

• What is energy?
• What is the relationship between potential energy and kinetic energy?
• How does the pendulum depict conservation of energy?
• What affect does weight have on the number of times the pendulum swings?

### Materials

• 1 large paper clip (per student)
• a watch of clock with a second hand
• string about 20/25 inches long
• a penny
• 2 small pieces of masking tape
• ruler
• scissors
• graph paper

### Procedure

Step One:

1. Use your ruler to measure out 25 inches of string for your pendulum. Make sure that everyone in the group measures out the same amount.
2. Tightly tie a paper clip to one end of the string.  Make sure its securely fastened.
3. Take out your pencil and create a small loop to fit through the pencil.
4. Use a small piece of masking tape to secure the string onto the pencil.
5. Take a penny and clip it onto the paperclip.

Step Two:

1. Secure the pendulum over the edge of a classroom table just enough for it to stick out slightly.
2. Look at the second hand of your watch to determine how many vibrations the pendulum move per 30 second(s), per minute(s).
3. Do this at least 3 times.
5. Repeat experiment by decreasing the length of the string and/or increase the weight by adding more pennies.

### Extension Activities

Mathematics

Use graph paper to record the results. Record the number of vibrations in 30 second increments ( y-axis) to the length of the string (x-axis).  Remember to have students label the graph paper before they begin.

Have students share their results

Language Arts/Science

Pendulums swing back and forth in a regular pattern. Each back and forth movement is called a vibration. The time it takes for one vibration is called a period. Explain, what if any does the effect of the length of string have on the period of a pendulum?

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