Bilingual edition: English is preserved and Chinese follows each unit. Terminology uses the confirmed v20260916 glossary; automated semantic review remains traceable.
中英双语版：英文原文完整保留，中文紧随对应单元；术语采用 v20260916 确认表，自动语义审校结果可追溯。

Stopping a Truck

刹车卡车

 Suppose a large truck and a small truck are moving with equal momentum. Which will require more work to stop? Which will require more force to stop in a given distance?

Discussion of the questions
问题讨论
假设有辆大卡车和一辆小卡车以相同的动量运动。要停下来，哪一辆需要更多的功？在给定的距离内，哪一辆需要更大的力？

 Index

Collision concepts
索引 碰撞概念
 
HyperPhysics***** Mechanics ***** Newton's laws
HyperPhysics ***** 力学 ***** 牛顿运动定律
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More force to stop a smaller truck?

更多的力来停下一辆小卡车？
 With equal momentum, the little truck will have more kinetic energy since kinetic energy depends upon the square of the velocity. With more kinetic energy, it will take more work to stop the smaller truck. Since work is equal to average force times stopping distance, the work-energy principle implies that it will take more force to stop the smaller truck in a given distance.
具有相同动量的小卡车将具有更多的动能，因为动能取决于速度的平方。由于动能更大，要停下来需要更多的功。由于功等于平均力乘以停止距离，功-能量原理表明，在给定的距离内，要停下来需要更大的力。
 Index

Collision concepts
索引 碰撞概念
 
HyperPhysics***** Mechanics ***** Newton's laws
HyperPhysics ***** 力学 ***** 牛顿运动定律
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How can it take more force to stop a smaller truck?

要停下来一辆小卡车需要更大的力吗？

If the big truck and the smaller truck have equal momentum, as stated in the equal momentum example, then the smaller truck will have to have a higher velocity. Since kinetic energy depends upon the square of the velocity, this implies that the smaller truck will have a higher kinetic energy. By the work-energy principle, then, it will take more work to stop the smaller truck.

如果大卡车和小卡车具有相等的动量，如等动量的例子中所述，那么小卡车必须具有更高的速度。由于动能取决于速度的平方，这说明小卡车的动能会更高。因此，根据功-能原理，要停止小卡车需要做更多的功。

If the trucks were traveling at the same speed, it would of course take more work to stop the bigger truck.

如果卡车以相同的速率行驶，要停下来显然需要更多的功。

Collision questions

碰撞问题
 Index

Collision concepts
索引 碰撞概念
 
HyperPhysics***** Mechanics ***** Newton's laws
HyperPhysics ***** 力学 ***** 牛顿运动定律
R Nave
 Go Back
返回