Pendulum Swing

About this printable Pendulum Swing science reading passage, NGSS-aligned (Grades 3-6)

This reading passage, designed for 4th-grade students, delves into the fascinating world of energy transformations using the example of a pendulum swing. Aligned with the NGSS disciplinary core concept PS3.B: Conservation of Energy and Energy Transfer, the passage explains how a pendulum's energy changes from potential energy, which is stored energy due to its position, to kinetic energy, which is the energy of motion. Students will learn that at the highest points of its swing, the pendulum has maximum potential energy and zero kinetic energy. As it swings downward, this potential energy is converted into kinetic energy, reaching its maximum at the lowest point. The passage uses simple language and an engaging narrative to help students grasp these fundamental concepts of physics and how energy is never created or destroyed, but simply changes form. The text includes definitions of key terms and a fun fact to keep students engaged. This resource is perfect for introducing the topic of energy to young learners.

Written by Workybooks TeamPublished by Workybooks

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Sample passage and quiz from Pendulum Swing

Pendulum Swing

A pendulum is a weight hanging from a string or rod that swings back and forth. You can see pendulums in clocks, playground swings, and even wrecking balls. A pendulum is like an energy see-saw—energy bounces back and forth between stored (potential energy) and moving (kinetic energy) with every swing!

At the very top of its swing, the pendulum is not moving. All its energy is stored as potential energy because of its height. As the pendulum starts to move downward, gravity pulls it down, turning potential energy into kinetic energy. The pendulum moves faster as it goes down.

At the bottom of the swing, the pendulum is moving the fastest. Here, almost all the energy is kinetic. As it swings up to the other side, the pendulum slows down. Its kinetic energy changes back into potential energy until it stops again at the top. This cycle repeats with every swing!

But a pendulum never swings forever. Friction with the air and at the pivot point (where the string is attached) takes away a little energy each time. This energy turns into heat, making the pendulum slow down and finally stop.

The speed of a pendulum’s swing depends only on the length of the string. A longer pendulum swings more slowly, while a shorter one swings faster. The weight of the pendulum does not change the speed!

Pendulums are used in real life to keep time in grandfather clocks, make playground swings fun, and help wrecking balls knock things down. The famous scientist Galileo discovered that pendulums take the same time to swing, no matter how heavy they are, by watching a lamp swing in a church.

Interesting Fact: The word "oscillation" means one full back-and-forth swing of a pendulum!