Question

A ball is dropped from the edge of a cliff. It lands 4 seconds later. What distance does the ball fall during the 4 seconds?

Answer 1

Given : -

A ball is dropped from the edge of a cliff.

To Find : -

Distance covered by ball in the first 4 seconds.

Solution : -

For a body falling freely under the action of gravity, g is taken positive.

For free falling; u = zero

Here acceleration due to gravity remains constant throughout the motion so we can apply equation of motion to solve this problem.

Second equation of motion for free falling object is given by,

$\sf \longrightarrow H = \dfrac{1}{2} gt^2$

By substituting the values, we get

$\longrightarrow \sf H = \dfrac{1}{2} \times 10 \times 4^2 \\\\\longrightarrow H = \dfrac{1}{2} \times 10 \times 16 \\\\\longrightarrow H = \dfrac{1}{2} \times 160 \\\\\longrightarrow H = 80$

Hence body will cover 80m distance in the first 4 seconds.