I want to derive some physics equations from other equations.(adsbygoogle = window.adsbygoogle || []).push({});

a) How can I derive this formula:

R=Vo^2(sin(sα) / -a

from these two equations:

(1) x=(Vo cosα)t

(2) y=(Vo sinα)t + 1/2at^2

Things I know

- I think the way to do this is to isolate the variable t in equation (1) and substitute the t in equation (2).

- Is the identity 2sin(theta) cos(theta)= sin(2theta) useful?

-When the projectile returns to its original level y=0

Please help me understand how to do this.

b) From equation

y=yo + Vyo t + 1/2at^2

how can I show that:

h= -1/2a(tf)^2

If I measure h and tf and recall that

a=-g sin (theta)

than this equation can be used to derive an equation for g in terms of tf, h and theta.

Please help!

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# Homework Help: Derive projectile equations. Please help!

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