newton's third law

[preety-disabled]

it is said that to every action there is equal and opposite reaction.
question:-if we throw mud on wall ,it sticks to it, and does not come back.please explain it?

[IRstuff]

On 6/17/2009 7:43:21 AM, preety wrote:
>it is said that to every
>action there is equal and
>opposite reaction.
>question:-if we throw mud on
>wall ,it sticks to it, and
>does not come back.please
>explain it?

Rebounding, as in the case of a thrown ball, only applies to "elastic" collisions, essentially, "bouncy" collisions. Mud is "inelastic," since any deformations remain, while deforming, by squeezing, a ball is temporary.

In any case, Newton's law still applies, but the reaction of a heavy wall, as expected, is miniscule, compared to the action of the ball. If you had sufficiently sensitive vibration sensors, you would detect the "bump" of the wall as the ball impacts.

TTFN,
Eden

[TomGutman]

Forces are between bodies. When the mud hits the wall there is a force between the mud and the wall. Newton's third law merely states that the force of the mud on the wall is the same as the force of the wall on the mud. It says nothing about the magnitude of either.

In the case of an inelastic collision (mud against the wall) the force of the wall on the mud (over the time of its application) is just sufficient to stop the mud. In an elastic collision (a bouncy ball against the wall) the forces are larger, and sufficient to propel the ball back with roughly the same speed as it had when it originally hit.

The mass and stiffness of the wall, together with its firm attachement to the ground, mean that the force of the mud or ball on the wall has no noticeable effect. That the bouncy ball exerts a greater force than the plastic mud has no observable effect.
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� � � � Tom Gutman