Question

jerica drops a pen and it free - falls for 3 sec. a) what was its instantaneous velocity? b) what is the distance it fell?

Explanation:

Step1: Recall free - fall equations

The equations for free - fall motion are $v = gt$ and $d=\frac{1}{2}gt^{2}$, where $g = 9.8\ m/s^{2}$, $v$ is the instantaneous velocity, $t$ is the time, and $d$ is the distance fallen.

Step2: Calculate the instantaneous velocity

Using the formula $v = gt$, with $t = 3\ s$ and $g = 9.8\ m/s^{2}$, we have $v=9.8\times3$.
$v = 29.4\ m/s$

Step3: Calculate the distance fallen

Using the formula $d=\frac{1}{2}gt^{2}$, with $t = 3\ s$ and $g = 9.8\ m/s^{2}$, we have $d=\frac{1}{2}\times9.8\times3^{2}$.
$d=\frac{1}{2}\times9.8\times9=44.1\ m$

Answer:

a) The instantaneous velocity is $29.4\ m/s$.
b) The distance it fell is $44.1\ m$.