Tuesday, October 9, 2012

Ruan Louw - Materials

Give a detailed explanation of the mechanics that are involved in the rotation of a body without translation.

It is possible to rotate a body without translation by two moments that are equal, paralle, in the opposite direction and noncollinear-an arrangement of forces called a couple. A couple always induces a pure
rotational tendency. A force applied at different points on the body will produce different movements, but it does not make any difference where a couple is applied. A momnet is one force producing a sliding
vector. A couple is two forces equal, parallel, opposite and noncollinear in producing a free vector.

3 comments:

  1. If one takes the definition of a force as an action of one body on another - a push or a pull, having magnified, direction and a point of application, and if this single force is applied to a free body on its centre mass, then translation will occur.

    So, the greater the force applied to a free body, the greater the translation.

    What do you think will happen if a force is applied away from the centre mass?

    Continue with the discussion

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  2. If the force is applied away from a centre of mass, the body will move exactly the same distance it would if the force were applied to the centre of the mass, but it also will turn on an axis, developing a moment.

    A moment is the tendency of a force to cause rotation of a body around the fixed axis. Given the same free body and the same force, a moment gives the same translation as if the force were applied through the centre of mass, but is also produces a rotational tendency. A equivalent moment can be produced by varying the force and the distance.

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  3. Well done guys. By the implementation of two forces (moments) that are equal, parallel, opposite in direction and non-collinear producing a free vector, it is possible to rotate a body without translation.

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