Question

Part A

Estimate the kinetic energy necessary for a projectile with mass m can "escape" from the surface of a planet if it is launched vertically upward. Express your estimation in terms of g which is the acceleration due to gravity at the planet's surface and Rp which is the planet's radius. Ignore air resistance.

i. The kinetic energy is about than 2mgRp.

ii. The kinetic energy greater than mgRp.

iii. The kinetic energy is about than 2mR2p/g.

iv. The kinetic energy greater than mR2p/g.

Part B

If the planet in question is the earth, at what temperature does the average translational kinetic energy of a nitrogen molecule (molar mass 28.0 g/mol) equal that required to escape? Use the radius of the Earth is Rp = 6370 km.

Express your answer in kelvins.

TN2,Earth = k

Part C

What about a hydrogen molecule (molar mass 2.02 g/mol)?

Express your answer in kelvins.

TH2,Earth = k

Part D

Repeat part B for the Moon, for which g = 1.63 m/s2 and Rp = 1740 km.

Express your answer in kelvins.

TN2,Moon = k

Part E

Repeat part C for the moon, for which g = 1.63 m/s2 and Rp = 1740 km.

Express your answer in kelvins.

TH2,Moon = k

Answer 1