
#1
Mar508, 05:40 AM

P: 7

Question is a golf ball is dropped from a height of 78m assuming gravity is 9.8 m s, What is the velocity of the ball after the first 10m.
I assume the equation to use is [tex]v^2=u^2+2ax[/tex] v = Final velocity u = Initial Velocity a = Acceleration x = Displacement So I plug in [tex]v^2 = 0+2(9.8ms)(10.0)[/tex] Now according to the answer sheet V should be 14.0 m s but no matter how I plug this in I cant seem to get the right answer. I think the problem is the way I am actually doing the math so if someone could perhaps step threw the maths so I can see where I went wrong. Thanks for any help 1. The problem statement, all variables and given/known data 2. Relevant equations 3. The attempt at a solution 



#2
Mar508, 05:48 AM

P: 363

you shoudnt only learn about plugging values into the formula, you should learn the physical meaning of the formula!!!!!!!!!! THAT IS VERY IMPORTANT I got 14 using the EXACT equation above, I believe you have made a careless mistake.




#3
Mar508, 05:48 AM

Math
Emeritus
Sci Advisor
Thanks
PF Gold
P: 38,877

No, no one can possibly tell you what you did wrong, because you haven't told us what you did! The equation you have, v^{2}= 2*9.8*10 is correct and gives v= 14 m/s. Apparently you made a mistake in the arithmetic, although it seems rather elementary to me! Since you didn't show what you did or tell us what answers you got, I can't tell if it was something as simple as forgetting to take the square root.




#4
Mar508, 05:53 AM

P: 7

Calculating Final Velocity
How embarrassing, oerg you where spot on I forgot to take the square of the answer I think I have been working at this too long tonight .
Thanks Again 


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