Question

In a fit of jealous rage, your significant other tosses your phone off a cliff. Determine how fast your phone with a mass of 0.264 kg is moving as it hits the ground 13 m below. (2 decimal places)

Answer 1

Given:

The mass of the phone is,

`m=0.264\text{ kg}`

The initial height of the phone is,

`H=13\text{ m}`

The initial potential energy of the phone will be converted into kinetic energy when it hits the ground.

If the velocity of the phone is v at the time of touching the ground we can write,

`\begin{gathered} (1)/(2)mv^2=mgH \\ v=\sqrt[]{2gH} \end{gathered}`

Substituting the values we get,

`\begin{gathered} v=\sqrt[]{2*9.81*13} \\ =15.9\text{ m/s} \end{gathered}`

Hence, the phone will have a speed of 15.9 m/s.