- #1
fsk08
- 3
- 0
Hi
First of all, this is not a homework question, but I'm sorry if it's in the wrong sub-forum.
I know that a football (soccer) has been kicked a distance of 5 meters using 0,16 seconds, that would give an average speed of 112,5 km/h, or approx 31 m/s. But since the speed of a football is given as inital speed, Vo, and not average speed, I was wondering if there is a way to figure out the initial speed when the average speed is known. Since the ball has no contact with the ground during the 5 meter flight, I guess that the only factor that reduces speed is drag/air resistance. I have tried to use the drag equation, but ended up with some extreme numbers which had to be wrong.
I can provide some exact entry values regarding the football itself (weight, circumference etc) if its needed.
I did find out that a baseball loses 1 mph per 7 feet of travel as a rule of thumb, which translates into roughly 1,5 kmh for every 2 meters. But I would guess that a football would lose more speed per meter than a baseball, because of the difference in size and weight. I guess the most simple way to find out the initial speed is to compare the aerodynamics of a baseball vs a football, and then use this rule of thumb to calculate the approx initial speed. But I don't know how more aerodynamic a baseball is compared to a football...
Any thoughts on this?
First of all, this is not a homework question, but I'm sorry if it's in the wrong sub-forum.
I know that a football (soccer) has been kicked a distance of 5 meters using 0,16 seconds, that would give an average speed of 112,5 km/h, or approx 31 m/s. But since the speed of a football is given as inital speed, Vo, and not average speed, I was wondering if there is a way to figure out the initial speed when the average speed is known. Since the ball has no contact with the ground during the 5 meter flight, I guess that the only factor that reduces speed is drag/air resistance. I have tried to use the drag equation, but ended up with some extreme numbers which had to be wrong.
I can provide some exact entry values regarding the football itself (weight, circumference etc) if its needed.
I did find out that a baseball loses 1 mph per 7 feet of travel as a rule of thumb, which translates into roughly 1,5 kmh for every 2 meters. But I would guess that a football would lose more speed per meter than a baseball, because of the difference in size and weight. I guess the most simple way to find out the initial speed is to compare the aerodynamics of a baseball vs a football, and then use this rule of thumb to calculate the approx initial speed. But I don't know how more aerodynamic a baseball is compared to a football...
Any thoughts on this?