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Notes from the field ·

Do Heavy Things Really Fall Faster? Drop Test, Parachutes and a Hammer on the Moon

By Ahmed, founder

Ask a child which falls faster, a bowling ball or a tennis ball, and most say the bowling ball. It’s not an unreasonable guess: everyday experience says heavy things drop hard. But it’s an idea that a simple test can overturn.

The drop test

You need: two identical containers (film canisters, small plastic tubs), something to fill one (coins or sand), a stepladder or high spot (adult supervised), and a floor that won’t be damaged.

  1. Fill one container with coins and leave the other empty. Check that they look the same.
  2. Predict: which will land first?
  3. Hold them side by side at the same height and let go at the same moment.
  4. Watch and listen. Repeat several times.

What happens

They land together, or so close that you can’t tell the difference. Some students will want to run it again, and that’s a good sign.

The explanation

Gravity pulls on all objects with the same acceleration (about 9.8 m/s² near Earth’s surface), regardless of mass. A heavier object gets pulled harder, but it also has more inertia, so the effects cancel out.

In everyday life we see differences, because of air resistance. A feather falls slowly because the air pushes back on it a lot compared with its tiny weight. In 1971, astronaut David Scott dropped a hammer and a feather on the Moon, where there’s essentially no air, and they hit the ground together.

Add parachutes

Make parachutes from plastic bags in three sizes, with string and a washer as a load. Drop each and time it, with at least three trials. Larger canopies catch more air, so they fall more slowly. Now you’re testing air resistance directly, and you have a fair test with a clear variable.

Measure the pull

Make a simple force meter with a rubber band and a ruler: the more weight you hang on, the more the band stretches. It shows that weight is a force, and it can be measured.

Common mix-ups

  • “Heavy things fall faster.” In a vacuum, no. In air, shape and size matter.
  • “There’s no gravity in space.” There’s gravity everywhere. Astronauts float because they’re in free fall.
  • “Air resistance is the same for all objects.” Larger area, more resistance.

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