Changing which way it goes
A push can change the way a moving thing is going.
Step 1: Something to Notice
Watch first. The explanation comes later.
A ball rolls toward you. You put your hand out in front of it. The ball turns around and rolls back the other way.
How did your hand change where the ball went?
Step 2: Find Out
This ball is already rolling. Watch what the hand does to it.
Step 1 — Predict
The ball is already rolling to the right. A hand is waiting in front of it. What will the ball do?
Choose what you think will happen. You cannot see the experiment until you do — guessing first is what makes it worth watching.
Step 3: So Here Is Why
Now the explanation, after you have seen it happen.
A push from the side turns it
Tap a rolling ball on the side. It turns and goes a new way.
A push from the front slows it
Hold your hand in front of it instead. A big enough push sends it back.
Step 4: A Common Mistake
Lots of people think
“Once something is moving, it has to keep going the same way.”
Step 5: In a Game
The same idea somewhere new.
In football a player kicks a rolling ball from the side. The ball does not stop — it turns and goes a new way.
Step 6: Think It Through
Practice makes it stick.
The Rolling Ball
Problem 1 of 1
A ball rolls toward Maya. She pushes it back. Which picture shows what happens?
Which Way Now?
1 of 3
A ball rolls toward you. You want to send it back. What do you do?
2 of 3
A ball is rolling away. You want it to come back. What do you do?
3 of 3
Put each picture in the right box.
Tap something to move it.
- Empty
- Empty
Step 7: Quick Check
Show what you know.
Question 1 of 1
Which one changes the direction something is moving?
What You Found Out
- A push or pull can change which way something moves.
- A push from the side makes it turn.
For the grown-up
Push from the side to turn — A ball rolling past you turns if you tap it on the side. It does not stop and it does not speed up much. It just goes a different way.
This is how steering works — Turning the handlebars on a bike makes the front wheel push the bike sideways a little. A boat has a rudder that does the same thing in water.