- #1
popo902
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Homework Statement
A gun has a muzzle speed of 80 meters per second.
What angle of elevation should be used to hit an object 150 meters
away? Neglect air resistance and use g = 9.8m/sec2 as the
acceleration of gravity.
Homework Equations
x = (vcos//theta)t
y = (vsin//theta)t - 1/2gt^2
g = 9.8 m/sec^2
The Attempt at a Solution
i substituted the given values:
x should be 150 and y should be 0 right?
150 = (80 cos\\theta)t
0 = ( 80sin\\theta)t - 4.9t^2
i can't figure out how to eliminate a variable or how to begin to solve for //theta
i solved for t using the "x" equation ( t = 15/8cos\\theta) and put that into the "y" equation
and i got this...
0 = 150tan//theta - 73.5/64(sec\\theta)^2
where do i go from here to find \\theta?