I am having the hardest time getting my range to match (at least I think they should). I used two range equations for the same problem as demonstrated below. I did it both ways to check my answer, and they are different. I was hoping you could tell me where I went wrong...I think my time of flight is incorrect.(adsbygoogle = window.adsbygoogle || []).push({});

v_0=105m/s

h=125m

Θ=37degrees

v_oy=63.19m/s (105m/s sin37)

v_ox=83.86m/s (105m/s cos37)

For my time of flight I used the equation y = v_0yt - 1/2gt^2 - h

Plugging in the numbers I get y = 63.19t - 1/2(9.8m/s)t^2 - 125

Rearranging the equation for quadratic, -4.9t^2 + 63.19t - 125

Then I use my quadratic formula and get

(-63.19(+-)39.28)/-9.8 thereby getting +2.349s and +10.45s. Neither of these fit when multiplied by my x of 83.86m/s. I get 196m and 876m.

For the problem I am checking the answer with is derived from the equation

R = v_o^2(sin2Θ)/g

So I get (105m/s)^2(sin2(37))/9.8m/s = 1081.41m

They don't match and they should, right?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Range Question

**Physics Forums | Science Articles, Homework Help, Discussion**