| 1. | He claimed to have done the work without help .
他声言未借助外力而完成了这项工作。 |
| 2. | Mass flow occurs as a result of external forces .
质体流动的发生是由于外力的结果。 |
| 3. | An external force is one whose source is outside the system .
外力是来源于系统之外的力。 |
| 4. | At equilibrium the resultant of all external forces vanish .
在平衡时，所有外力的合力为零。 |
| 5. | The external forces include reactions (r)as well as applied loads(p) .
外力包括反力R和施加力荷载P。 |
| 6. | The velocity of the center of mass is constant in the absence of external forces .
在无外力时，质心的速度是常量。 |
| 7. | An outside agent exerts a force p of sufficient magnitude causes to spring to stretch .
施足够大的外力P，使弹簧拉长。 |
| 8. | The easiest way to rid a system of external torque is to rid it of all external forces .
要去掉系统的外转矩，最简易的办法是去掉一切外力。 |
| 9. | Acceleration always has the direction of the net force, regardless of the direction of the velocity .
加速度的方向总是与净外力的方向一样，而与速度的方向无关。 |
| 10. | This effect is due to the high radial compression produced by the external forces acting at the supports .
此种效应是由于作用在支点的外力所产生的高度径向压缩而引起的。 |
