# m2 projectiles question

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#1
http://pasteboard.co/8AuYWqiEF.jpg

I tried resolving horizontally, and making T the subject and doing the same vertically and I got
-49/15 = 98Tan(a) - 2g/cos^2(a)
which I don't think can be simplified to the given equation. I tried it multiple times and am still getting the same answer
0
3 years ago
#2
Can you post all your working?
0
3 years ago
#3

the time T it takes to reach the ground is 98/{49cosα}

substitute this into

s = ut + 1/2 a T2 where

s = - 3& 4/15

u = 49sinα

a = -9.8

with a bit or re-arrangeing it comes out correctly.
0
#4
Nevermind, they used sec^2x = tan^2x + 1 formula which I didn't expect in M2
0
3 years ago
#5
no, thank you
0
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