anyone wanna help me with a physics problem

aceofskies05

Senior member
Jun 13, 2006
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14. A golfer can hit a golf ball a horizontal distance of over 300 m on a good drive. What maximum height will a 301.5 m drive reach if it is launched at an angle of 25.0° to the ground? (Hint: At the top of the flight, the ball?s vertical velocity component will be zero.)

the answer is 35, but I cant seem to figure it out. I got it all drawn out, but I feel like they dont give enough information.
 
Oct 25, 2006
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Its just a parabola.

It accelerates downward at a constant 9.8 m's. So figure out how the the ball stays in the air, divide it by 2, the plug it into the equation that figures out the change in the y direction
 

JohnCU

Banned
Dec 9, 2000
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remember that the vertical and horizontal movements are independent of each other
 

RESmonkey

Diamond Member
May 6, 2007
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I can do this problem, but I don't know what a fucking drive is. I'm guessing it's the horizontal distance the golf ball traveled?

wait, this is just trigonometry.

2nd edit = Nope, I don't think you haven enough information to do this problem.
 

frostedflakes

Diamond Member
Mar 1, 2005
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You are missing something -- initial velocity. What you should be able to do is use the equation for vertical motion to solve for initial velocity as a function of t, and then plug that into a horizontal motion equation to solve for time. Once you have that, you can solve for initial velocity, and then the height.

If you still need help I can scan and upload a solution.
 

TuxDave

Lifer
Oct 8, 2002
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Originally posted by: RESmonkey
Unless drive means something different, you can't do this problem.

Why not? You can solve for the initial velocity (Along the 25 degree line) and then solve for the height at its peak.
 

Eeezee

Diamond Member
Jul 23, 2005
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Damn, I came into this thread too late :( Oh well, yes, find the time it's in the air and use that to find the maximum height. It takes a little bit of algebra because you're not given the velocity, but it's a pretty good intro problem. Good luck!
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
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www.slatebrookfarm.com
Originally posted by: tenshodo13
Its just a parabola.

It accelerates downward at a constant 9.8 m's. So figure out how the the ball stays in the air, divide it by 2, the plug it into the equation that figures out the change in the y direction

Actually, for the problem, you're supposed to assume the path is parabolic. A golf ball's flight certainly is not parabolic though. Of all the "real world" physics problems, I find problems involving golf balls to be the most annoying.

edit: by combining several of the more basic equations, you can come up with an equation for range, in terms of theta and the initial velocity. Since you have theta and the range, you can solve that equation to find the initial velocity. From there, find the vertical component of velocity & you should be good for figuring out the maximum height from there.

But still, it irritates me when someone tries to treat golf ball problems as semi-realistic when the spin on the golf ball (and the dimples) have a huge affect on the flight path and range.

Oh, and 300m isn't that realistic. Here's both paths & PGA driving distances:
http://www.golfjoy.com/golf_physics/dynamics.asp
 

Freshgeardude

Diamond Member
Jul 31, 2006
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I swear I am in the same book as you are, actually I am in the same book as you, just did this problem yesterday I think. though, I forgot the formula on how to do it.


edit: Yes it does not take into account wind resistance or any of that, this is a basic physics class, at least for me this book is from a 1st year class