Which is the rocket equation for the speed gain?

• Delta v equals exhaust speed times log of mass ratio
• Delta v equals exhaust speed plus mass ratio
• Delta v equals mass ratio over exhaust speed

A rocket has no ground or air to push against. How does it move?

• It throws mass backward and momentum pushes it forward
• It pushes against the launch tower
• It sails on the solar wind

Two rockets share the same exhaust speed and the same mass ratio, but one is ten times heavier. Which gains more speed?

• The heavier one
• The lighter one
• Neither: only the ratio matters

Why is the rocket equation called unforgiving?

• A bit more speed wants a lot more fuel
• Fuel adds speed in exact proportion
• Small rockets cannot reach orbit

Why does staging beat carrying one large tank?

• It raises the exhaust speed
• It stops you hauling dead weight around
• It removes gravity

To set up the momentum balance, which system do you pick?

• The rocket body alone
• The rocket plus the gas it is about to eject
• The exhaust gas alone

Doubling the fuel load doubles the speed gain of a rocket.

Sam says rockets push against air, so they cannot work in empty space. What is wrong?

• Rockets do need air, only higher up
• Nothing external is needed: ejected mass carries the momentum
• Rockets push against starlight instead