Lesson – Paperclip Pendulums
Title: Paperclip Pendulums
Grade: 6th Grade
Duration: 45 Minutes
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.
- 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 __________________.
Can you show the law of conservation of energy?
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.
- 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?
1 large paper clip (per student)
a watch of clock with a second hand
string about 20/25 inches long
2 small pieces of masking tape
- 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.
- Tightly tie a paper clip to one end of the string. Make sure its securely fastened.
- Take out your pencil and create a small loop to fit through the pencil.
- Use a small piece of masking tape to secure the string onto the pencil.
- Take a penny and clip it onto the paperclip.
- Your pendulum is complete.
- Secure the pendulum over the edge of a classroom table just enough for it to stick out slightly.
- Look at the second hand of your watch to determine how many vibrations the pendulum move per 30 second(s), per minute(s).
- Do this at least 3 times.
- Record your findings.
- Repeat experiment by decreasing the length of the string and/or increase the weight by adding more pennies.
- Record your findings
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
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?