What is the maximum total impulse for a 'J' rocket motor?

What is the maximum total impulse for a 'J' rocket motor?

• A. 320.00 Newton-seconds
• B. 640.00 Newton-seconds
• C. 1280.00 Newton-seconds
• D. 2560.00 Newton-seconds

Answer: (C)

Total impulse is the thrust delivered integrated over the burn time, and it’s used to categorize motors into letter classes. Each letter covers a specific range of total impulse. For the J class, the range runs up to the upper limit of 1280 Newton-seconds. That means the maximum total impulse you can have in a J motor is 1280 N·s; anything just above that would fall into the next class, starting at around 1280.01 N·s. So 1280 N·s is the highest impulse permissible for a J motor.

Total impulse is the thrust delivered integrated over the burn time, and it’s used to categorize motors into letter classes. Each letter covers a specific range of total impulse. For the J class, the range runs up to the upper limit of 1280 Newton-seconds. That means the maximum total impulse you can have in a J motor is 1280 N·s; anything just above that would fall into the next class, starting at around 1280.01 N·s. So 1280 N·s is the highest impulse permissible for a J motor.