Question

Choose the correct statement for the rocket engine

• A. thrust decreases with altitude
• B. flight speed always less than jet velocity
• C. rate of climb decreases with altitude
• D. engine has no ram drag

Hint:

Ram drag is absent in rockets because they don’t rely on atmospheric air.

Answer 1

The Correct Option is D

In the context of rocket engines, various characteristics set them apart from other propulsion systems like jet engines. Let's assess the given options to determine which statement accurately describes a feature of rocket engines:

Thrust decreases with altitude: In general, rocket engines are designed to operate in space or at high altitudes where there is little to no atmospheric pressure. Unlike air-breathing engines, rocket engines do not rely on atmospheric oxygen and can produce consistent thrust regardless of altitude, as they carry both fuel and oxidizer onboard.

Flight speed always less than jet velocity: This statement is not an intrinsic characteristic of rocket engines. While the maximum speed of a vehicle using rocket propulsion can vary, the rocket's jet velocity can be very high, often greater than the speed of the vehicle.

Rate of climb decreases with altitude: Rocket engines generally maintain or even increase efficiency at higher altitudes due to reduced atmospheric drag and consistent thrust production, so this statement does not accurately describe a universal characteristic related to rocket engines.

Engine has no ram drag: This is the correct statement. Rocket engines do not experience ram drag because they do not ingest high-speed atmospheric air, unlike ramjets or other air-breathing engines which do face significant ram drag as air is compressed and decelerated within the engine intake.

Thus, the statement that accurately describes a characteristic of rocket engines is: "engine has no ram drag".