Free Fall Physics Example 3

Follow the full solution, then compare it with the other examples linked below.

easy

An object is dropped from a height of

80 \text{ m}

. How long does it take to hit the ground? Use

g = 10 \text{ m/s}^2

1
Use $d = \frac{1}{2}gt^2$ and solve for $t$ .
2
$t = \sqrt{\frac{2d}{g}} = \sqrt{\frac{2 \times 80}{10}} = \sqrt{16} = 4 \text{ s}$

Answer

t = 4 \text{ s}

The time of fall depends only on the height and gravitational acceleration, not on the mass of the object.

About Free Fall

Motion under gravity alone, with no air resistance — all objects in free fall accelerate at $g \approx 9.81$ m/s² regardless of mass.

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