A body is acted upon by a set of non-concurrent coplanar forces. If $y_c$ and $Y_c$ be the positions

Question

A body is acted upon by a set of non-concurrent coplanar forces. If $y_c$ and $Y_c$ be the positions of centre of mass and centre of force of the system, then

Professor PC Thomas Classes · Answer

When the center of force $Y_c$ coincides with the center of mass $y_c$, then the angular acceleration of the body is zero.
- Linear acceleration a becomes zero when $\sum F=0$, not necessarily when $Y_c=y_c$
- $a=0$ and $\alpha=0$ cannot occur simultaneously in case non-concurrent coplanar forces.
- $a$ can be zero but $\alpha$ cannot be zero.