Physics horizontal velocity and height, just tell me if this is correct?

romeo is chucking pebbles gently up to juliet's window, and he wants the pebbles to hit the window with only a horizontal component of velocity. He is standing at the edge of a rose garden 8.0 m below her window and 9.0 m from the base of the wall. How fast are the pebbles going when they hit her window?



t = (sqrt)2h/g = 1.3 seconds

horizontal velocity = 6.9 m/s



so is the answer 6.9 m/s ? i'm not sure and my teacher marks off points for wrong answers

Physics horizontal velocity and height, just tell me if this is correct?
your answer is correct ... depending on the value you use for g (g=9.81m/s^2 is good enough for me) and if you keep more than two significant figures for the intermediate result (t=1.3s) you might end up with a final answer of 7.0m/s ... depends whether how picky your teacher is about these things.



I know you might show more work on your assignemnt than you did here ... that is always a good idea because that shows you really understand what you are doing (even a few words sometimes helps to explain what you are doing)



just for future reference, probably the way to write the first equation so that it is easiest for others to figure out what you mean is

t = sqrt(2h/g)
Reply:Both answers are correct, but write sqrt(2h/g) and show all your work.
Reply:Yes.

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