Answer:
velocity of ball A after the collision is 1.8 m/s, 49.1° above the horizontal
Step-by-step explanation:
This is a conservation of elastic momentum in 2 dimensions problem.
initial momentum must equal final momentum: pi = pf
Break up the pf of B into its x and y components to solve. Since the balls are identical, you can leave mass (m) out of the calculations:
x: 2 + 0 = 1.6(cos60) + Ax
Ax = 1.2 x component of velocity of ball A after the collision
y: 0 + 0 = -1.6(sin60) + Ay
Ay = 1.3856 y component of velocity of ball A after the collision
R-A = √(1.2² + 1.3856²) = 1.83 ≈ 1.8 m/s resultant velocity of ball A after the collision
∅ = tan⁻¹(¹1.3856/1.2) = 49.1⁰ angle ball A is going after the collision