A ball is released from rest at the edge of a cliff and falls freely through a height of h = 20 m (g = 9.8 m/s²). Determine the time it takes to reach the ground.

Dynamics Challenge #1 — Kinematics

Free fall
from a cliff.

Dynamics Easy

Problem

A ball is released from rest at the edge of a cliff and falls freely through a height of \( h = 20\ \mathrm{m} \). Determine the time it takes to reach the ground below.

Initial velocity\( v_0 = 0 \)
Height\( h = 20\ \mathrm{m} \)
Gravity\( g = 9.8\ \mathrm{m/s^2} \)
Answer inseconds

Ignore air resistance.

Hint: the ball starts from rest, so \( v_0 = 0 \). Which kinematic equation links the distance fallen, the acceleration and the time when the initial velocity is zero?

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Free fallfrom a cliff.

Problem

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Free fall
from a cliff.