A 1 kg ball and a 10 kg ball are dropped together from the top of a tall tower. If air resistance is ignored, which reaches the ground first?

Both reach the ground togetherCorrect answerYour answerThe 10 kg ballCorrect answerYour answerThe 1 kg ballCorrect answerYour answerThe 10 kg ball, in one-tenth of the timeCorrect answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer A

Correct answer: A

Every falling body has the same acceleration due to gravity, g, whatever its mass.
The heavier ball feels a larger force, but it also has more inertia, and the two cancel.
With the same acceleration from the same height, they land together.

Worth noting

In real air a feather falls slower than a stone because of air resistance, not because it is lighter.

Concept: Acceleration due to gravity is independent of mass
Typical timeTypical: 90 s
Your timeYours: —

The rule this testsMotion, force and pressure

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Ten questions from Everyday Physics, at your own pace.

A 1 kg ball and a 10 kg ball are dropped together from the top of a tall tower. If air resistance is ignored, which reaches the ground first?

Explanation