Energy-Changing Machines
Aligned to 4-PS3-4 — Next Generation Science Standards.
What this lesson teaches
Devices can change energy from one form into another to do a job. A flashlight changes stored energy in a battery into light, and a wind-up toy changes motion you make into motion that moves the toy.
Worked examples
Example 1
A hand-crank flashlight changes the motion of your turning hand into electric energy, and that electric energy becomes light — with no batteries needed.
Example 2
A water wheel turns the motion of a river into spinning motion that can grind grain or run a generator.
Example 3
A battery stores chemical energy and releases it as electric energy. Every device you plug in is a machine for changing energy from one form to another.
Practice questions
- Look at a wind-up or battery-powered toy. What energy goes into it, and what energy comes out?
- Sketch a simple device that turns moving water into spinning motion, like a water wheel.
- Design a toy that changes one kind of energy into another, and describe how it works.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Máquinas que cambian la energía
Los aparatos pueden cambiar la energía de una forma a otra para realizar un trabajo. Una linterna cambia la energía guardada en una pila en luz, y un juguete de cuerda cambia el movimiento que tú haces en movimiento que mueve al juguete.
Ejemplo 1: Una linterna de manivela cambia el movimiento de tu mano al girar en energía eléctrica, y esa energía eléctrica se convierte en luz — sin necesidad de pilas.
Ejemplo 2: Una rueda de agua convierte el movimiento de un río en movimiento giratorio que puede moler grano o mover un generador.
Ejemplo 3: Una pila guarda energía química y la libera como energía eléctrica. Cada aparato que conectas es una máquina para cambiar la energía de una forma a otra.
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