Projectile Motion Problem with no Velocity given

Jun 2016
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England
You start with the standard velocity acceleration displacement equation:

S=S0+V0t+1/2At^2

Where S is the height above the ground
and A is the acceleration due to gravity
t is time.

Then it a simultaneous equation situation:
you know A (=g=9.82 m/s/s)
you know two values for S (at the start and at the wall)

From this you should be able to work out V0
(note that this is just the vertical component, use some trigonometry to get the horizontal component).
 
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Jan 2019
44
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$\Delta x = v_0\cos{\theta_0} \cdot t \implies t = \dfrac{\Delta x}{v_0\cos{\theta_0}}$

$\Delta y = v_0\sin{\theta_0} \cdot t - \dfrac{1}{2}gt^2$

eliminate the parameter, $t$

$\Delta y = \Delta x \tan{\theta_0} - \dfrac{g \cdot \Delta x^2}{2v_0^2 \cos^2{\theta_0}}$

evaluate where necessary & substitute the given values and solve for $v_0$
 
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