Gravity (objects fall down)

The idea

Let go of a spoon and it falls. Trip over a rock and you fall too. Gravity is the pull that drags everything down toward the ground. You cannot see gravity, but you can see what it does everywhere: rain falls, leaves drift down, a thrown ball always curves back to the grass. Gravity never turns off and never takes a day off — it pulls all day and all night, on every single thing.

The pull of gravity always points the same way: down, toward the ground under your feet. Things do not fall sideways or up. Even when a ball sits still on a shelf, gravity is still pulling on it — the shelf is simply holding it up. A common mix-up: a floating balloon seems to ignore gravity. It does not. Gravity pulls the balloon down too, but the air around the light balloon pushes it up even harder, the way water pushes up a beach ball. Without that helper push from the air, the balloon would drop like everything else.

Worked example

At the playground, you drop a tennis ball 10 times: from knee height, from the top of the slide steps, over the grass, and over the sandbox. Before each drop you ask which way the ball will go. What do the 10 drops show?

1. Drop the ball from knee height 3 times over the grass. Every time it goes straight down and lands by your feet — never up, never sideways.
2. Climb the slide steps and drop it 3 times from up high. It still falls straight down; from higher up it simply has farther to fall, so the trip takes a little longer.
3. Drop it 4 times over the sandbox while facing different directions. No matter where you stand or face, down is the same way: toward the ground.
4. Count the results: 10 drops, 10 falls toward the ground, 0 surprises. When the same thing happens every single time, you have found a rule of nature.
5. Check the rule against your memory: dropped crayons, spilled juice, and falling rain all do the same thing, so the rule is not just about tennis balls.

Answer. All 10 drops ended the same way: the ball fell down toward the ground, because gravity pulls everything down every time.

Check your understanding

• What strange things would happen at breakfast if gravity stopped pulling for one minute?
• Why does a helium party balloon rise even though gravity is pulling it down the whole time?
• Where does 'down' point for someone standing on the other side of the world, and why is that puzzling to think about?
• What clues show that gravity is still pulling on a book even while it sits perfectly still on a table?

Keep going

← All Elementary School physics concepts