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Homework Statement
- A ball is thrown at 22 m/s at 45 degrees to the horizontal. A 5 foot tall fence is located 100 meters away. Does the ball make it over the fence?
keithcuda said:Homework Statement
- A ball is thrown at 22 m/s at 45 degrees to the horizontal. A 5 foot tall fence is located 100 meters away. Does the ball make it over the fence?
Homework Equations
View attachment 77761
The Attempt at a Solution
SteamKing said:You've written some numbers down, but whether they mean anything is another story.
What's the deal with v_{f} - v_{i} = -31.12? [You need to show units in your calculations always.] What does this even mean, in terms of the travel of the ball?
Roy Hobbs ;)Bystander said:Who's throwing? Randy Johnson? Or Warwick Davis?
Your attachment can't be opened.keithcuda said:Here is my image and drawing with all of the units shown.. Sorry for not including them earlier.
https://www.physicsforums.com/attachments/77770
keithcuda said:Here is my image and drawing with all of the units shown.. Sorry for not including them earlier.
https://www.physicsforums.com/attachments/77770View attachment 77771
Quantum Defect said:Ok, I understand what you are doing now.
On the line with Delta v, you are stating that at the point that the ball impacts the ground, the downward velocity is the same magnitude as the upward velocity at the launch, but with opposite direction. You use the calculated Delta v and g to calculate the time aloft, and you use the horizontal component of the velocity times the time aloft to calculate the distance traveled. You note that since the distance traveled (49 m) < 100 m, the ball hits the dirt in front of the wall.
This looks good to me.
I would suggest adding some words to describe the equations -- to show that you know what you are doing. If you screw up the calculation (arithmetic error) but have the correct physics, your professor might give you some partial credit...
OH boy! Ummm...TSny said:How high can that ball bounce?
CWatters said:Playing the devil... Suppose the distance traveled had worked out at 102m. Would the ball have cleared the wall?