Answer:
The distance the ball moves up the incline before reversing its direction is 3.2653 m.
The total time required for the ball to return to the child’s hand is 3.2654 s.
Explanation:
When the girl is moving up:
The final velocity (v) = 0 m/s
Initial velocity (u) = 4 m/s
a = -0.25g = -0.25*9.8 = -2.45 m/s². (Negative because it is in opposite of the velocity and also it deaccelerates while going up).
Let time be t to reach the top.
Using
v = u + a×t
0 = 4 - 2.45*t
t = 1.6327 s
Since, this is the same time the ball will come back. So,
Total time to go and come back = 2* 1.6327 = 3.2654 s
To find the distance, using:
v² = u² + 2×a×s
0² = 4² + 2×(-2.45)×s
s = 3.2653 m
Thus, the distance the ball moves up the incline before reversing its direction is 3.2653 m.
