Answer:
A. 7.1m
B. 3.55m/s
C. 1.775m/s^2
Step-by-step explanation:
First step is to identify given parameters;
Ball 1: m₁ = 0.5kg, u (initial velocity) =0, t = 2seconds
Ball 2: m₂ = 0.25kg, u = 15m/s, t = 2seconds
Second step: we determine the y-coordinate of ball 1 after 2 seconds, using the equation of motion under gravity as shown below;



Recall, that the ball was thrown from a height of 25m, total y-coordinate of ball 1 after 2 seconds becomes 25m +(-19.6m)
[tex]y_{1} = 5.4m[/tex]
Third step: we determine the y-coordinate of ball 2 after 2 seconds


Fourth step: we determine the y-component of the center mass of the two balls


y = 7.1m
Fifth step: we solve B part of the question; velocity of the center mass of the two balls


velocity = 3.55m/s
Sixth step: we solve C part of the question; acceleration of the center mass of the two balls


acceleration = 1.775 m/s^2