(Solved): 7. In the famous hammer vs. feather dropping experiment on the moon, the feather falls a distance H ...

7. In the famous hammer vs. feather dropping experiment on the moon, the feather falls a distance $H$ to the moon's surface over a time $t$. What is the correct expression for the acceleration due to gravity, $g_M$, on the moon? A) $\frac{1}{2}H{t}^2$ B) $\frac{H}{t}$ C) $\sqrt{\frac{H}{2t^2}}$ D) $\frac{2H}{t^2}$ E) Cannot be determined from the information given 8. A rock of mass $m$ is thrown straight up into the air with initial speed $?v_0?$ and initial position $y=0$ and it rises up to a maximum height of $y=h$. A second rock with mass $2\mathrm{m}$ (twice the mass of the original) is thrown straight up with an initial speed of $2?{\mathrm{v}}_0?$. What maximum height does the second rock reach? A) $0.5\mathrm{h}$ B) $\mathrm{h}$ (same as first rock) C) $2\mathrm{h}$ D) $4\mathrm{h}$ E) None of the above