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I was watching a YouTube video on projectile motion:

It says that the range is given by the formula:

d = v*cosθ*t

It also says that the time to reach the maximum height is given by the formula:

t = [itex]\frac{v*sinθ}{a}[/itex] where v*sinθ is the initial vertical velocity

Well, not necessarily, but I derived that from:

v = u+at

So you multiply that by 2 to get the total time which gives you:

t = [itex]\frac{2*v*sinθ}{a}[/itex]

Put that into the original formula and you get:

d = 2*v*cosθ*([itex]\frac{v*sinθ}{9.81}[/itex])

d = [itex]\frac{2*sinθ*cosθ*v

My aim was to plot the range of the projectile at a given angle. However, when I plot this graph using Graphmatica, it is just an oscilating graph, resembling the sine or cosine functions...

Where have I gone wrong? Either a simple mistake, or this was never going to work in the first place.

Thanks for any help.

It says that the range is given by the formula:

d = v*cosθ*t

It also says that the time to reach the maximum height is given by the formula:

t = [itex]\frac{v*sinθ}{a}[/itex] where v*sinθ is the initial vertical velocity

Well, not necessarily, but I derived that from:

v = u+at

So you multiply that by 2 to get the total time which gives you:

t = [itex]\frac{2*v*sinθ}{a}[/itex]

Put that into the original formula and you get:

d = 2*v*cosθ*([itex]\frac{v*sinθ}{9.81}[/itex])

d = [itex]\frac{2*sinθ*cosθ*v

^{2}}{9.81}[/itex] -- meant to be 2*sinθ*cosθ*v^{2}/9.81My aim was to plot the range of the projectile at a given angle. However, when I plot this graph using Graphmatica, it is just an oscilating graph, resembling the sine or cosine functions...

Where have I gone wrong? Either a simple mistake, or this was never going to work in the first place.

Thanks for any help.

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