CenterofMassReferenceFrame

CenterofMassReferenceFrame - the CM is zero relative to the...

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Center of Mass Reference Frame It is often more convenient to analyze a problem in the CM reference frame because the math involved is often simplified. Ex. a) Find V cm of two particles, each mass of 1 kg, moving in same direction. One particle is moving at 10 m/s and the other at 20 m/s. 11 2 2 12 (1 )(10 / ) (1 )(20 / ) 11 15 / cm cm cm mv mv V mm k g ms k g ms V kg kg Vm s + = + + = + = 1kg 1kg V 1 =10 m/s V 2 =20 m/s V cm =15 m/s +X +Y b) What is the velocity of the center of mass in the center of mass reference frame? ZERO!! 1. In the CM reference frame the velocity of the CM is zero.
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Unformatted text preview: the CM is zero relative to the CM.) Since P sys = M V cm , then P sys = 0 since V cm = 0 in the CM reference frame. This is sometimes referred to as the zero-momentum RF. 2. Two particles, before a collision in the CM reference frame, must have equal and opposite momenta. m 1 m 2 V 1 V 2 V cm cm m 1 m 2 U 1 U 2 cm Original RF CM RF V cm =0 A. After a perfectly inelastic collision the objects remain at rest. B. After a 1D elastic collision, the velocity of the particles are equal and opposite to their initial velocities....
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This note was uploaded on 09/02/2011 for the course PHYS 4a taught by Professor Luna during the Spring '11 term at DeAnza College.

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