Idea 5of 7Builds onChange needs a net forceMass fights backDown is free fall
Heavy and light fall together
A bowling ball and a golf ball, dropped together. Which first?
Today you'll discover
- two balls released together, step by step
- why more pull does not mean a faster fall
- what every mass has in common on the way down
Think firstA heavy ball and a light ball, released together
No air. A heavy ball and a light ball, released together. Which lands first?
Predict first, then press Next. Watch whether the two balls stay level.
A large ball and a small ball at a line near the top of the picture. After a prediction, the frames advance: both balls drop by the same growing amount each step, a dashed line joining them at the same height, with brackets down the right measuring the drops. The last step asks the fall times of a one-kilogram and a ten-kilogram ball.
See the whole ideathe big idea and the key word, in one place
The big idea
More pull on more mass: everything free-falls at g.
Compare themWeight is ten times bigger on the 10 kg ball. So is the mass that resists. Divide, and the same 9.8 m/s² comes out.
About this modelWithout air, every mass falls the same way; the lag appears only when air pushes back.
Without air, every mass falls the same way; the lag appears only when air pushes back.
Ready to use it?
- Explain why two masses released together land together when air is ignored.