请输入您要查询的字词:

 

单词 impulse
释义
impulse

Physics
  • Symbol J. The product of a force F and the time t for which it acts. If the force is variable, the impulse is the integral of Fdt from t0 to t1. The impulse of a force acting for a given time interval is equal to the change in momentum produced over that interval, i.e. J=m(v1v0), assuming that the mass (m) remains constant while the velocity changes from v0 to v1.


Mathematics
  • The impulse J associated with a force F acting during the time interval from t = t1 to t = t2 is the definite integral of the force, with respect to time, over the interval. Thus J is the vector quantity given by

    J=t1t2Fdt.

    Suppose that F is the total force acting on a particle of mass m. From Newton’s second law of motion in the form F = (d/dt)(mv), it follows that the impulse J is equal to the change in the linear momentum of the particle.

    If the force F is constant, then J = F(t2t1). This can be stated as ‘impulse = force×time’.

    The concept of impulse is relevant in problems involving collisions.

    Impulse has the dimensions MLT−1, and the SI unit of measurement is the kilogram metre per second, abbreviated to kgms−1.


Chemical Engineering
  • 1. A quantity used to measure the total change in momentum of a body produced by a force acting on the body for a very short time.

    2. In process control, it is a disturbance to a process that occurs over a very short period of time.


Biology
  • The signal that travels along the length of a nerve fibre and is the means by which information is transmitted through the nervous system. It is marked by the flow of ions across the membrane of the axon caused by changes in the permeability of the membrane, producing a reduction in potential difference that can be detected as the action potential. The strength of the impulse produced in any nerve fibre is constant (see all-or-none response).

    http://nerve.bsd.uchicago.edu/ Details of nerve impulses and other aspects of neurophysiology


随便看

 

科学参考收录了60776条科技类词条,基本涵盖了常见科技类参考文献及英语词汇的翻译,是科学学习和研究的有利工具。

 

Copyright © 2000-2023 Sciref.net All Rights Reserved
京ICP备2021023879号 更新时间:2024/12/26 3:27:24