# Applying a force on a rigid body on a certain point

I have a rigid body with an origin point (at the center of mass).

I want to apply a force on a certain point.

So what is the force applied to the origin of this rigid body?

Description image:

Note: I don't want the moment of torque.

More explanation:

Assume $p$ is a point in the space of a rigid body.

So if we had a force $\vec F_{p}$ at a point $p$, how can we get the $\vec F_{center}$?

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## 1 Answer

Any force applied to any part of a rigid object acts on the object as a whole. So if you were to place a directional force meter at the center of the object (or at any other point on the object), it would register the force $\vec{F}_p$.

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but if it wasn't in the center , it will cause a torque . how does the energy still the same as if without torque ? –  MhdSyrwan Nov 4 '11 at 17:27
Because the rotation imparted by the force means that it takes more work to push the body obliquely. –  Ron Maimon Nov 4 '11 at 19:33
could you explain more please ? –  MhdSyrwan Nov 4 '11 at 23:24