a)  p₀ = 1.2 kg m / s
b) p_f = 1.2 kg m / s  
c)     = 1.278 m/s
 = 1.278 m/s
d)1.2482 = cos θ
 cos θ
e)  0.2736 = sin θ
sin θ
g) θ = 12.36
<h3>
What is momentum?</h3>
Momentum is the product of the mass of a particle and its velocity. Momentum is a vector quantity; i.e., it has both magnitude and direction.
According to the question,
We define a system formed by the two balls, which are isolated and the forces during the collision are internal.
Hence , the momentum is conserved
a) The momentum of the system before the collision:

b) The momentum of the system after the collision, as the system is isolated, the momentum is conserved so

d. On X axis
 = 1.2 kg m / s
 = 1.2 kg m / s
 = m v1f cos 20 + m v2f cos θ
= m v1f cos 20 + m v2f cos θ

1.2 = 0.6 (-0.8) cos 20+ 0.6 cos θ
 cos θ
1.2482 = cos θ
 cos θ
e. On Y axis  

 = m
= m sin 20 + m
sin 20 + m cos θ
cos θ
 0 = 0.6 (-0.8) sin 20 + 0.6  sin θ
 sin θ
 0.2736 = sin θ
sin θ
Here,
g. we write our system of equations
0.2736 = sin θ
 sin θ
1.2482 =  cos θ
 cos θ
0.219 = tan θ (divide)
 θ = tan⁻¹ 0.21919
 θ = 12.36
c. Now To find the velocity
0.2736 =  sin θ
 sin θ
  = 0.2736 / sin 12.36
= 0.2736 / sin 12.36
 = 1.278 m / s
 = 1.278 m / s
Learn more about momentum here:
brainly.com/question/4956182
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