- #1
Hedgehog1
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Homework Statement
A cannon is fired at a target on a cliff that is 400 meters away. The cliff has an elevation of 150 meters relative to the cannon. The initial velocity of the cannonball is 100 m/s. Ignoring wind resistance calculate the two possible angles and their respective times.
X= 400m
Y=150m
V_naught=100m/s
A= -9.81 m/s^2
Homework Equations
Time X = Time Y
X=V_naught*cos(theta)*t
Y= V_naught*sin(theta)*t - 0.5*a(t)^2
1/(cos(theta)0^2=1+ (tan(theta))^2
The Attempt at a Solution
t= 400/100cos(theta)
0= -0.5*a(t)^2 + V_naught*sin(theta)*t -150
0= -0.5*a(400/100cos(theta))^2 + V_naught*sin(theta)*400/100cos(theta) -150
I get stuck here. I'm not really quite sure what to do next. I'm pretty sure I have to use the quadratic equation, but don't know how.