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PinkFlamingo
Jun4-04, 01:04 AM
I'm sorry for posting so often, but I'm really stuck on these :cry:

A cannon having a muzzle speed of 1000 m/s is used to destroy a target on a mountaintop. The target is 2000 from the cannon horizontally and hoom above the ground. At what anle, relative to the ground, should the cannon be fired (ignore air friction).

I don'[t really know what to do with this either, except that the V0 in the x-direction is 1000 m/s and the V0 in the y-direction is 0 m/s and the acceleration in the y-direction is 9.81

I don't really know where to go from here. any help would be super appreciated! :yuck:

arildno
Jun4-04, 02:10 AM
Please remove the numerous typos here; I don't understand which parameters are present in this exercise :confused:

Gza
Jun4-04, 02:48 AM
I don'[t really know what to do with this either, except that the V0 in the x-direction is 1000 m/s and the V0 in the y-direction is 0 m/s and the acceleration in the y-direction is 9.81

by making this assumption, you imply that the answer is 0 degrees. The problem only gives you the magnitude of the muzzle velocity I assume. This is a projectile motion problem, so all you have to do is break up the motion into the horizontal and vertical directions. In the horizontal direction, the velocity will be constant at V_o\cos \theta , vertical magnitude for initial velocity will be V_o\sin \theta . There is of course an acceleration of gravity vertically so take that into account as well with a kinematical relation. Then just solve for theta.