(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

You are in charge of a cannon that exerts a

force 19000 N on a cannon ball while the ball

is in the barrel of the cannon. The length of

the cannon barrel is 1.92 m and the cannon is

aimed at a 37° angle from the ground.

The acceleration of gravity is 9.8 m/s^2.

If you want the ball to leave the cannon

with speed v0 = 79.3 m/s, what mass cannon

ball must you use?

2. Relevant equations

W=∫_{C}F•dx

3. The attempt at a solution

I already have done the problem, the answer is 11.56kg. My question is if the way I solved this problem was ok. i got several points docked for the way I answered it.

I wanted to make sure I understood the concept well enough to apply it to more complex problems, such as ones where the path taken by an object was not a straight line and the force varied with position, so I made the path taken into a vector valued function r(t) where 0≤t≤1 (t is arbitrary since I'm calculating work right?) and then combined the force of gravity with the force exerted by the cannon into a force field existing along the path taken by the cannonball. I calculated drfrom the vector-valued function, and solved the line integral. Of course the whole thing only turned out to be the force dotted into the path taken by the cannonball anyways, but I was just trying to make sure I understood the concept.

So my question is this: is there something wrong with the way I solved the problem?

Edit: I meant "work problem" not word problem, my apologies.

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# Homework Help: Is this an ok way to solve this word problem?

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