- #26

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Touch'eIf you launch an identical projectile from 6 metres above the ground, with the same firing angle (45 deg), at 100m it will now clear a fence 12 metres high.

Ok, I'm lost... No matter what I do to the simultaneous equations. I never get the right answer

This is what I did

6=-9.81t^2 + y*(sin45 = 0.7071)----------------1

100=y*(cos45 = 0.7071)*t ----------------------2

make y the subject for eqn 2.

y=100/0.7071t

Sub y value into eqn 1

-6=-9.8t^2*(100/0.7071t)*0.7071

"0.7071" a "t" from -9.8t^t cancel out because of "0.7071" under the "100"

-6=-9.8t+100

100+6=9.8t

106/9.8 = 9.8t/9.8

9.24=t

I know I MUST have made a mistake but the worst part is that I cant see it