- #1

Hedgehog1

- 4

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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.