As long as two forces have the same magnitude and are in opposite directions, these two forces form a couple.
举一反三
- As long as two forces have the same magnitude and are in opposite directions, these two forces form a couple. A: 正确 B: 错误
- For two forces to cancel, they must act on the same object.
- The two balls move _______ the opposite directions _______ the same stress.
- A ship sails from 179ºE to 179ºW. Meanwhile, the other ship sails from 1ºE to 1ºW, which one is correct of the following choices______: A: Both the magnitude and direction of D'long for the two ships are equal B: Both the magnitude and direction of D'long for the two ships are unequal C: The magnitudes of D'long for two ships are equal, but the directions of D'long are unequal D: The magnitudes of D'long for two ships are unequal, but the directions of D'long are equal
- Suppose that both the cross-sectional area A and the length L of two straight rods are the same, and the axial tension forces P at both ends of the two are also the same. Only the materials of the two rods are different. Which statement about the stress σ and the elongation ΔL of the two rods is right?__________