(a) Show that m2 (vi)1 – ÜCM Au, mi + m2 and -Aŭ. m1 + m2 That is, m2Aï/(m1 + m2) represents the velocity of particle 1 relative to the centre of (üi)2 – UcM mass, and similarly for particle 2. (b) Starting from P, = m1(j)1 + m2(0,)2, and P, = m1(ü,)ı + m2(ūs)2, show that the total momentum is P = P; = (m1 + m2)ūcM- That is, the uCM terms carry the total momentum, while the momenta of the Au terms add up to zero. (c) Starting from K = }m(v;){ + }m2(v.)3, show that the total kinetic energy of the system can be written: m2 Av mi +m2. m1 Av mi + m2 1 1 K = ; (m, + m2)vồm +m 5m2

icon
Related questions
Question
and then writing the velocities of particles 1 and 2 before and after the collision as
m2
(T:)2 = JCM
-Aŭ;
mị + m2
= ÜCM +
and
mi + m2
m2
m1
(7s)2 = ŪCM +
-Aī.
mi + m2
and
=
mi + m2
(a) Show that
m2
(v)1 – ŪCM
Aī,
mị + m2
and
(v)2 – ÜCM
m1 + m2
That is, m2Aŭ/(m + m2) represents the velocity of particle 1 relative to the centre of
mass, and similarly for particle 2.
(b) Starting from P = m1(v)1 + m2(ū)2, and P; = m1(üs)1 + m2(T;)2, show that the
total momentum is
P = P; = (m1 + m2)īcm-
That is, the ücM terms carry the total momentum, while the momenta of the Au terms
add up to zero.
(c) Starting from K = }m(v;){ + }m2(v;);, show that the total kinetic energy of the
system can be written:
m2 Av \?, 1
+
m Δυ
(m, + m2.
1
1
K = ;(m, + m2)vćm + 2m1 (m1 + m2,
That is, the kinetic energy separates into a part associated with the centre of mass, and
another part that represents motion relative to the centre of mass, with no cross-terms
involving ucMAJ.
(d) Consider now a (partly) inelastic collision, in which the final velocities are (ū;)ı and
(üs)2. Show that the minimum kinetic energy of the particles after the collision is
1
K = (m, + m2)vCM:
For this minimum kinetic energy, What is the velocity of the particles relative to each
other after the collision, and what kind of collision is this?
Transcribed Image Text:and then writing the velocities of particles 1 and 2 before and after the collision as m2 (T:)2 = JCM -Aŭ; mị + m2 = ÜCM + and mi + m2 m2 m1 (7s)2 = ŪCM + -Aī. mi + m2 and = mi + m2 (a) Show that m2 (v)1 – ŪCM Aī, mị + m2 and (v)2 – ÜCM m1 + m2 That is, m2Aŭ/(m + m2) represents the velocity of particle 1 relative to the centre of mass, and similarly for particle 2. (b) Starting from P = m1(v)1 + m2(ū)2, and P; = m1(üs)1 + m2(T;)2, show that the total momentum is P = P; = (m1 + m2)īcm- That is, the ücM terms carry the total momentum, while the momenta of the Au terms add up to zero. (c) Starting from K = }m(v;){ + }m2(v;);, show that the total kinetic energy of the system can be written: m2 Av \?, 1 + m Δυ (m, + m2. 1 1 K = ;(m, + m2)vćm + 2m1 (m1 + m2, That is, the kinetic energy separates into a part associated with the centre of mass, and another part that represents motion relative to the centre of mass, with no cross-terms involving ucMAJ. (d) Consider now a (partly) inelastic collision, in which the final velocities are (ū;)ı and (üs)2. Show that the minimum kinetic energy of the particles after the collision is 1 K = (m, + m2)vCM: For this minimum kinetic energy, What is the velocity of the particles relative to each other after the collision, and what kind of collision is this?
1. In class in Lectures 19 and 20 we treated elastic collisions by first calculating the quantities
m1(T;)1+ m2(T;)2
and
Au = (7;)1 – (T;)2,
mi + m2
Transcribed Image Text:1. In class in Lectures 19 and 20 we treated elastic collisions by first calculating the quantities m1(T;)1+ m2(T;)2 and Au = (7;)1 – (T;)2, mi + m2
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps with 3 images

Blurred answer