Lesson 21 of 84 · Forces and Motion
Lesson⭐ 30 XP⚡ Spark LabHow Machines Help Us
Forces and Motion.
🎯 Your mission
Learn the rule. Then catch nature using it.
⚡ The twist
The opposite of what you expect is often what happens.
Mind = Blown
🎢 You feel weightless on a roller coaster because you and the seat are falling at the same speed.
Make a hypothesis first
Predict: what happens if you double the force?
What You'll Learn
A force is a push or pull that can change an object's motion, shape, or direction. Forces are measured in Newtons and can act through contact or at a distance.
Key Words
- pulley
- inclined plane
Steps
Read about Forces and Motion and write down three key facts.
Set up a pendulum with string and a washer. Change the string length and count swings per minute for each. Graph your results.
Note any unexpected results and think about why they happened.
Share your findings with the class or a partner and discuss what you learned.
Check Your Understanding
Question 1
1 of 3Which is an example of potential energy?
Where you see this in real life
You use this every time you flip a light switch, ride a bike, or kick a ball.
Stretch Challenge
Try this in real life this week.
Time how long a small ball rolls down something, then change the slope and try again.
For the dinner table
“Show me something at home that uses this kind of energy.”
Next Smart Experiment
We'll pick an experiment that matches exactly how you're thinking right now.
Share this experiment
Send it to a parent who's looking for a 10-minute kitchen science win.
Checkout complete lesson on Forces and Motion for 3rd Grade
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