Model rocket
Performance
The impulse (area under the thrust-time curve) of a model motor is used to determine its class. Motors are divided into classes from 1/4A to O and beyond.

Model rocket

Section Title: Performance
Table Section Text: The impulse (area under the thrust-time curve) of a model motor is used to determine its class. Motors are divided into classes from 1/4A to O and beyond.

Class	Total Impulse (Metric Standard)

1/4A	0.313-0.625 N·s

1/2A	0.626-1.25 N·s

A	1.26-2.50 N·s

B	2.51-5.0 N·s

C	5.01-10 N·s

D	10.01-20 N·s

E	20.01-40 N·s

F	40.01-80 N·s

G	80.01-160 N·s

Sentence(s)

The total impulse of a "C" motor is 5.01-10.0 N-s and "B" motor is 2.51-5.0 N-s.
In Model rocket, the impulse of C motors are in the 5.01-10.0 N-s range, while "B" motors are in the 2.51-5.0 N-s range.

final_sentence: The total impulse of a "C" motor is 5.01-10.0 N-s and "B" motor is 2.51-5.0 N-s.
final_sentence: In Model rocket, the impulse of C motors are in the 5.01-10.0 N-s range, while "B" motors are in the 2.51-5.0 N-s range.