Answer:
B) 225 m/s^2
Explanation:
The rock hits the ground at 15m/s and travels 50cm=0.5m through the ground until it stops.
The acceleration is supposed to be uniform, so the formula we have to use is [tex]v^2=v_0^2+2ad[/tex], which for acceleration is:
[tex]a=\frac{v^2-v_0^2}{2d}[/tex]
Taking the downwards direction as positive (the direction of traveling, so the initial velocity and displacement will be positive), substituting our values for that movement we have:
[tex]a=\frac{v^2-v_0^2}{2d}=\frac{(0m/s)^2-(15m/s)^2}{2(0.5m)}=-255m/s^2[/tex]
Where the negative sign indicates that it is pointing upwards.
