After simplification of any force system in space, a force and a couple are obtained. The magnitude of this force is ( ) the principal vector of the force system.
A: equal to
B: more than
C: less than
D: not equal to
A: equal to
B: more than
C: less than
D: not equal to
举一反三
- The cutting force of 45 steel after normalizing is ( ) that of 45 steel after quenching and tempering. A: smaller than B: larger than C: equal to D: uncertain
- According to the U. S Air Force organization system, --------has always been the Air Force prime war-fighting system? A: the air division B: the wing C: the NAF D: the group
- __________ does not support topic sentence: I would sooner be in the Air Force than any other service branch. A: a. I’m more interested in flying than in any other military occupation. B: b. There are greater opportunities for advancement in the Air Force. C: c. Service in the Air Force is far more exciting than that in the Navy. D: d. My cousin went to college after his graduation from high school.
- The magnitude of a moment is the product of the force and（）.
- To describe a force, we only need to describe the magnitude that describe "how hard" the force pushes or pulls.