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Precepts
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Homework Statement
Calculate the range if a sniper stands and raises his barrel to an angle of 30 degrees above the horizontal with the end of the barrel 2.0 m above the ground. The muzzle velocity of his rifle is 800m/s.
Known variables:
U = 800ms^-1
Uv = 400m/s
Uh = 692.8m/s
a = -9.8m/s
Homework Equations
V = u + at
v^2 = u^2 + 2as
s = ut + 1/2at^2
The Attempt at a Solution
Sh = Uh x t
In order to find t, I doubled the time to the apogee:
Vv = u + at
0 = 400 x -9.8t
9.8t = 400
t = 40.8 sec. (apogee)
Therefore time of flight = 81 sec. (This is obviously wrong... using this in the range equation gives too large a number). So I don't know where to go from here. The launching at an angle + a height is confusing me, I'm just not seeing it.