a ball is fired from a cannon at an angle of 40 degrees to the horizontal and it travels 300m before hitting the side of a cliff which is 10 meters higher than the cannons position.(adsbygoogle = window.adsbygoogle || []).push({});

Determine the initial velocity.

The ball has a negative velocity when it hits the cliff.

My attempt:

Where v = the balls initial velocity

y component of velocity = -9.81t + Vsin40

integrate this and get

y position = .5*-9.8t^2 + vsin40t

x component of velocity = vcos40

integrate this and get

x position = vcos40t

Using the expression for x velocity, solve for t at 300m in the x direction and get the expression

t=300/vcos40

Sub this into the expression for the y position above and solve for v.

I'm unsure if this is the correct way to go about doing this. The velocity I ended up with is 42.7124ms^-1 which seems a bit slow for the distance it covers.

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# Homework Help: Projectile motion of a cannon ball

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