Question

part a
an apple falls from a tree and hits the ground 5 meters below with a speed of about
5 m/s.
15 m/s.
10 m/s.
20 m/s.
not enough information

Explanation:

Step1: Identify the relevant kinematic equation

We use $v^{2}=v_{0}^{2}+2gh$. The initial velocity $v_{0} = 0$ (starts from rest), $g = 10m/s^{2}$ (approximate acceleration due to gravity) and $h=5m$.

Step2: Substitute values into the equation

Substituting $v_{0} = 0$, $g = 10m/s^{2}$ and $h = 5m$ into $v^{2}=v_{0}^{2}+2gh$, we get $v^{2}=0 + 2\times10\times5$.
$v^{2}=100$.

Step3: Solve for $v$

Taking the square - root of both sides, $v=\sqrt{100}=10m/s$.

Answer:

C. 10 m/s