Question

question 9 of 10
youre conducting a physics experiment on another planet. you drop a rock from a height of 2.1 m and it hits the ground 0.6 seconds later. what is the acceleration due to gravity on this planet?
a. 5.2 m/s²
b. 11.7 m/s²
c. 7.0 m/s²
d. 9.8 m/s²

Explanation:

Step1: Identify the kinematic - equation

The kinematic equation for free - fall motion with initial velocity $u = 0$ is $h=ut+\frac{1}{2}gt^{2}$. Since $u = 0$, the equation simplifies to $h=\frac{1}{2}gt^{2}$, where $h$ is the height, $g$ is the acceleration due to gravity, and $t$ is the time.

Step2: Rearrange the equation for $g$

From $h=\frac{1}{2}gt^{2}$, we can solve for $g$:
\[g=\frac{2h}{t^{2}}\]

Step3: Substitute the given values

We are given that $h = 2.1$ m and $t = 0.6$ s. Substitute these values into the formula:
\[g=\frac{2\times2.1}{0.6^{2}}=\frac{4.2}{0.36}\approx11.7\ m/s^{2}\]

Answer:

B. $11.7\ m/s^{2}$