Thrust-to-weight ratio is defined as what?

Thrust-to-weight ratio is defined as what?

• A. It is the rocket weight divided by the thrust of the motor.
• B. It is the thrust of the motor divided by rocket weight.
• C. It is the total impulse divided by the airframe length.
• D. It is the thrust minus weight ratio.

Answer: (B)

The main idea is to compare how hard the engine can push against how much the rocket weighs. Thrust-to-weight ratio is defined as thrust divided by weight. Weight is the gravitational force acting on the rocket, not just its mass, so T/W = thrust / weight. Since weight equals mass times gravity, this ratio also tells you how many g’s of acceleration the rocket would experience (T/W times g). If the ratio is greater than 1, the rocket can lift off and accelerate upward; if it’s less than 1, it won’t. Why the other options don’t fit: inverting the ratio would give weight over thrust, which isn’t the defined measure; using total impulse divided by airframe length mixes a different concept (impulse over size) and isn’t the thrust-to-weight ratio; and subtracting thrust minus weight gives a net force, not a ratio.

The main idea is to compare how hard the engine can push against how much the rocket weighs. Thrust-to-weight ratio is defined as thrust divided by weight. Weight is the gravitational force acting on the rocket, not just its mass, so T/W = thrust / weight. Since weight equals mass times gravity, this ratio also tells you how many g’s of acceleration the rocket would experience (T/W times g). If the ratio is greater than 1, the rocket can lift off and accelerate upward; if it’s less than 1, it won’t.

Why the other options don’t fit: inverting the ratio would give weight over thrust, which isn’t the defined measure; using total impulse divided by airframe length mixes a different concept (impulse over size) and isn’t the thrust-to-weight ratio; and subtracting thrust minus weight gives a net force, not a ratio.