How would I delete an object that I no longer need in an animation? I am animating a projectile, but once it's out of view, I don't want my computer to have to process it anymore. Is there any way for me to delete it after I'm done with it?
You can animate the renderability of the object.
Move the mouse over the camera icon on the outliner and set a keyframe (just press i or right-click and select insert keyframe) then move to the frame where you want the object to disappear, disable renderability by pressing on the camera icon and set a new keyframe.
Note that the interpolation for visibility is always Constant.