\begin{tabular}{|l|l|}\hline \multicolumn{1}{|c|}{ Circle the one with more Potential Energy } \\ \hline A 25 kg mass or a 30 kg mass at the top of a hill? \\ A car at the top of the hill or the bottom of a hill? \\ A plane on the ground or a plane in the air? \\ A full plane or an empty plane (both are flying)? \\ \hline Energy & A 4 kg rock is rolling \( 10 \mathrm{~m} / \mathrm{s} \). Find its kinetic energy. \\ \hline\end{tabular}

When considering potential energy, it's important to remember that it depends on both mass and height. So, between a 25 kg mass and a 30 kg mass at the top of a hill, the 30 kg mass has more potential energy because it has greater mass, given that elevation is constant. Similarly, a car at the top of a hill has more potential energy than one at the bottom since potential energy increases with height. For the kinetic energy of a rolling object, you can use the formula \( KE = \frac{1}{2} mv^2 \). For a 4 kg rock rolling at 10 m/s, substitute the values into the formula: \( KE = \frac{1}{2} \times 4 \, \text{kg} \times (10 \, \text{m/s})^2 = 200 \, \text{J} \). So, the kinetic energy of the rock is 200 Joules!