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Science Launch G3 / Week 02 / Friday
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Week 02 · Motion Patterns

Friday

Pendulums tell time
// Swings that repeat
⏱ about 15 min

Friday: Pendulums Tell Time

In a museum hallway, Rocket stops beside a tall wooden clock. Inside, a long pendulum swings: tick, tock, tick, tock.

"How does a swinging weight tell time?" Rocket asks.

Raven listens closely. "What do you notice about the ticks?"

Nova taps the beat with her wing. "Count them," she says. "Do they ever speed up?"

Clocks that swing

Long ago, people wanted clocks that kept good time.

In 1656, a Dutch scientist named Christiaan Huygens made the first pendulum clock.

His early clock was off by less than 1 minute a day. That was a big deal back then.

In a pendulum clock, gravity makes the pendulum swing back and forth.

The clock counts the swings to measure time. The steady pattern keeps it accurate.

CLOCK CHECK
  • Read the question.
  • Tap your answer.
What does a pendulum clock count to measure time?
Why is a steady swing pattern useful in a clock?
A motion that repeats is a ____.
A shorter pendulum swings ____.
Using a pattern to say what comes next is to ____.
Week reviewTrue or false?
A pendulum clock counts swings to tell time.?
Adding weight to the bottom makes a pendulum swing faster.?
A swing at the park moves in a pattern.?
WHY THIS EXERCISEWeight at the bottom did not change the swing, but length did.

Patterns all around

Pendulum clocks are not the only steady patterns.

A park swing, a seesaw and a marble in a bowl all repeat.

When something repeats, we can predict its next move.

Huygens used that idea. A steady swing made a clock that kept good time.

CLOCK HISTORY
  • Read the question.
  • Tap your answer.
Who made the first pendulum clock?
In what year was the first pendulum clock made?
HOW A PENDULUM CLOCK KEEPS TIME
  • ?Gravity pulls the pendulum down.
  • ?The pendulum swings to one side.
  • ?It swings back again.
  • ?The clock counts the swing.
  • ?The hands move forward.
WHY THIS EXERCISEThe pendulum swings in a steady pattern, and the clock counts each swing.
Huygens' early clock was off by less than how many minutes a day?
WHY THIS EXERCISEHis early clock was off by less than 1 minute a day.
On paper, sketch a pendulum clock. Label the pendulum and show which way it swings.

You found patterns, built a pendulum and learned how clocks count swings. Tomorrow is Launch Lab!

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