Question

Question 6.14 A molecule in a gas container hits a horizontal wall with speed 200 m s–1 and angle 30° with the normal, and rebounds with the same speed. Is momentum conserved in the collision? Is the collision elastic or inelastic?

Chapter Work, Energy And Power Page 136

Answer 1

Hey there !!!!!!

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Momentum is independent of type of collisions as it is always conserved.

As rebound speed of gas molecule is same as initial speed So rebound velocity of wall of container is zero.

So kinetic energy remains same and also momentum is conserved.

It is an example of elastic collision .

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Hope this helped you....................................

Answer 2

Yeah , linear momentum is conserved .
because we know,
Linear momentum will be conserved only when External force acting on system equals zero. here, in collision, Fext = 0
hence Linear momentum is conserved .

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again, question says that molecule hits the horizontal walls and rebound with speed .
it means
kinetic energy of molecule before collision = kinetic energy after collision
e.g kinetic energy of molecule is conserved , this is possible only in an ELASTIC collision .

Hence, collision is elastic collision .
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