A rubber ball is thrown straight down from a height of 244 feet at speed of 80 feet per second. If the ball always rebounds with one-fourth of its impact speed, what will be the speed of the ball the third time it hits the ground?
My Answer is:
1/4*80=60
1/4*60=45
1/4*45=33.75
1/4*33.75=25.31 for the speed
Or I need to use some kind of formula? Please help me.
I am not sure what the formula is, but I can tell you that 1/4 multiplied by 80 is not 60. It would be 20. 60 is 3/4 of 80.
Yes what I meant is that it decreased 1/4 of every its impact, so therefore the answer would be 60 mph after first impact.
Your approach to finding the speed of the ball the third time it hits the ground is correct. You correctly applied the fact that the ball always rebounds with one-fourth of its impact speed.
To break it down step by step:
First, the ball is thrown down with an initial speed of 80 feet per second. When it hits the ground for the first time, it rebounds with one-fourth of its impact speed. Therefore, the speed after the first bounce is (1/4) * 80 = 20 feet per second.
On the second bounce, the ball is thrown downward again with an initial speed of 20 feet per second. It rebounds with one-fourth of this speed, so the speed after the second bounce is (1/4) * 20 = 5 feet per second.
Finally, on the third bounce, the ball is thrown downward with an initial speed of 5 feet per second. Again, it rebounds with one-fourth of this speed, giving us (1/4) * 5 = 1.25 feet per second.
So, the speed of the ball the third time it hits the ground is approximately 1.25 feet per second.