Ball

1
Ball A and Ball B have the same mass- 1.0 kg
Ball A is moving toward Ball B. Ball B
is stationary
Ball B
Ball A
2
When A travels at 2.0 m/s and strikes B, Ball
B moves upward at 35o and Ball A moves
downward at 55o .
Whatever momentum A has before the collision
A and B share after they collide
rb
ra
35o
55o
ra
mva mvb mva mv2
1.0 kg x 2.0 m/s 0 mva mvb
2.0 kg m/s ra rb
3
rB
rB
rA
35o
35o
rA
rA
rA
rb Cos35 x 2.0 kg m/s
rb 1.6 kg m/s
rA
ra Sin 35 x 2.0 kg m/s
rB
ra 1.1 kg m/s
rA
35o
4
rB
35o
rA
rb Cos35 x 2.0 kg m/s
rA
rb 1.6 kg m/s
vb rb /mb vb 1.6 kg m/s / 1 kg 1.6 m/s
rA
rB
ra Sin 35 x 2.0 kg m/s
rA
ra 1.1 kg m/s
35o
va ra /ma va 1.1 kg m/s / 1 kg 1.1 m/s
5
rBx Cosq1 rB
rA rBx rAx
rBy Sinq1 rB
rBy
rB
rBx
q1
rA
q2
rAx
rA
rAy
rAx Cosq2 rA
rAy Sinq2 rA
0 rBy rAy
6
p p
mvA mvACosq2 mvBCosq1
vBy
vB
vBx
q1
vA
q2
vAx
vA
vAy
7
Two balls of equal mass strike each other. Ball
A moves at 5.20 m/s and strikes ball B, which is
stationary. After the collision ball A travels
above the original path at an angle of 21.00.
What is the p and vs of each ball after the
collision? The mass is 2.0 kg.

• rA Cosq1 rA rA Cos 21.00 x 10.40
  m/s rA 9.7 kg m/s
• rA mvA vA 9.7 kg m/s /
  2.0 kg vA 4.85 m/s

2. rB Sinq1 rB rB Sin21.00 x
10.40 m/s rB 3.73 kg m/s rB
mvB vB 3.73 kg m/s / 2.0 kg vB
1.86 m/s