Question

a st wants to know the effect of mass on ke. he will drop 2 balls of the same size in a pool. which investigation fits? drop 2 balls with different masses from different heights drop 2 balls of the same mass from different heights drop 2 balls with different masses from the same height drop 2 balls of the same mass from the same height

Explanation:

Step1: Understand the principle of kinetic energy (KE)

Kinetic energy formula is \(KE=\frac{1}{2}mv^{2}\). To study the effect of mass (\(m\)) on \(KE\), other variables (like velocity \(v\)) should be controlled. Velocity of a falling object \(v = \sqrt{2gh}\) (from \(v^{2}=u^{2}+2gh\), \(u = 0\) for free - fall). So, to have the same \(v\), balls should be dropped from the same height \(h\).

Step2: Analyze each option

• Option 1 (red): Different masses and different heights. Since \(h\) is different, \(v\) will be different. Can't isolate the effect of \(m\) on \(KE\).
• Option 2 (blue): Same mass. Can't study the effect of \(m\) on \(KE\).
• Option 3 (yellow): Different masses, same height. \(v\) is same (as \(v=\sqrt{2gh}\), \(h\) is same). So \(KE\) difference is only due to \(m\).
• Option 4 (green): Same mass. Can't study the effect of \(m\) on \(KE\).

Answer:

drop 2 balls with different masses from the same height (yellow option)