Question 772: Centre of Mass and Rotational Motion

Question

If the resultant of all the external forces acting on a system of particles is zero, then from an inertial frame, one can surely say that

Accepted Answer

According to Newton's second law, we have
$$\sum {{{\overrightarrow f }_{ext}} = {{d\overrightarrow p } \over {dt}}} $$
If $$\sum {{{\overrightarrow f }_{ext}} = 0} $$, we find that the linear momentum $$\overrightarrow p $$ as constant.

Answer

Linear momentum of the system does not change in time.

Answer

Kinetic energy of the system does not change in time.

Answer

Angular momentum of the system does not change in time.

Answer

Potential energy of the system does not change in time.

Centre of Mass and Rotational Motion

If the resultant of all the external forces acting on a system of particles is zero, then from an inertial frame, one can surely say that

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