[برنامج العالم]

السسؤال بالانجليزي ..
A ball is thrown with starting velocity equal to 20m\s at an angle of 45 degrees.
when the ball bounces off the ground it loses 20% of its velocity

1) how many times does the ball need to bounce to reach the 100m mark ?

2) ? at what height will the ball be when it reaches the 75m mark

Note : the angle doesn't change when bouncing .