Question

table 2: heights and speeds of five identical planes if the planes were not identical, what further information would have been needed and why? a) the masses of the planes would have been needed to compare gravitational potential energies only. b) wind speed data would have been needed to compare the gravitational potential energies of the planes. c) the masses of the planes would have been needed to compare gravitational potential energies and kinetic energies. d) the elasticity of the materials used to make the planes would have been needed to compare their gravitational potential energies.

Explanation:

• Gravitational potential energy formula: \(U = mgh\) (where \(m\) is mass, \(g\) is acceleration due to gravity, \(h\) is height). Kinetic energy formula: \(K=\frac{1}{2}mv^{2}\) (where \(m\) is mass, \(v\) is speed).
• If planes are not identical, mass (\(m\)) is a variable. To compare gravitational potential energies (\(U\)) and kinetic energies (\(K\)), mass is needed as it is a factor in both formulas.
• Wind speed (\(B\)) is not relevant to gravitational potential energy (\(U = mgh\)) or kinetic energy (\(K=\frac{1}{2}mv^{2}\)) calculations. Elasticity (\(D\)) is not related to \(U\) and \(K\) for this context. Option \(A\) is incorrect as mass is also needed for kinetic energy comparison.

Answer:

C. The masses of the planes would have been needed to compare gravitational potential energies and kinetic energies.