- #1

#### devanlevin

this is a question in kinematics and the only force to take into account is gravity,

using

V(t)=Vo+at

X(t)=Xo+Vot+½at²

V²-Vo²=2aΔx

Vx=const=cosθ*Vo

Vy(t)=sinθ*Vo+at

Vo=500m/s

Xf=10000m

Yf=500m

knowing that the target is at (10000,500) i use the equation for X,

X(tf)=500cosθ*tf=10000m

tf=20/cosθ

Y(tf)=500m=500sinθ*(20/cosθ)-4.9*(20/cosθ)²

=1000tanθ-1960/(cosθ)²

now from here i don't know what to do, one equation with both tanθ and cosθ, how do i bring them to some common expression?? i have had a very similar quesion before which i too could not get past this point.

since i do not have T, i thought of using the 3rrd equation, but i don't see how i can