Conservation of momentum with friction?

Thread starter raman911
Start date Nov 13, 2007
Tags

Conservation Conservation of momentum Friction Momentum

AI Thread Summary

Momentum is conserved in isolated systems, but external forces, such as friction, can affect the total momentum observed. In the case of colliding pucks, while momentum is conserved during the collision, friction acts as an external force that gradually reduces their speed to zero. This results in a loss of momentum over time, which does not violate the conservation law as the system is not isolated. The change in momentum is caused by the work done against friction, which dissipates energy and slows the pucks down. Therefore, the apparent violation of momentum conservation is explained by the influence of external forces like friction.

Nov 13, 2007

raman911

Homework Statement

We know that momentum is supposed to be conserved in this collision. We observe, however, that the pucks eventually come to a stop, at which point they have zero momentum. Give a solid explanation (using the law of conservation of momentum) for this apparent violation of the law of conservation of momentum.

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Nov 13, 2007

G01

Science Advisor

Gold Member

What causes a change in momentum?

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