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Homework Help: Hey physics instant velocity ques

  1. Sep 30, 2004 #1
    If an arrow is shot upward on the moon with a velocity of 58m/s, its height in meters after t seconds is given by h=58t-0.83t^2

    find the instantaneous velocity after one second....can u post ur work?? and explain this to me......thx in advance...
  2. jcsd
  3. Sep 30, 2004 #2


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    Instant Velocity is

    [tex] \vec{V} = \frac{d \vec{r}}{dt} [/tex]

    If you have this formula, then the first derivative is speed. For velocity, remember to put the j, because it's 1D motion in the y-axis.

    [tex] h=58t-0.83t^2 [/tex]
  4. Sep 30, 2004 #3
    its for a calculus class and we arent allowed to use derivtives yet.......so for that forula u gave me what number would i plug in???? im kinda confused....i did a table of values with time intervals to average velocity but the whole one second i dont understand.....can u show me like an answer......im sorry ur rules are u not doing my hmk...i seriously have tried i just dont understand...
  5. Sep 30, 2004 #4


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    You could graph that function, and pick really close values for time and h, to calculate the slope.

    The First derivative is the slope.

    Slope formula
    [tex] m = \frac{\Delta h}{\Delta t} [/tex]
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