# Homework Help: More kinematics

1. Jun 4, 2004

### PinkFlamingo

I'm sorry for posting so often, but I'm really stuck on these

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:

2. Jun 4, 2004

### arildno

Please remove the numerous typos here; I don't understand which parameters are present in this exercise

3. Jun 4, 2004

### Gza

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.