 But there's a catch. If you are watching closely, you may be wondering whether theta angle has disappeared too. Well, usually we consider the speed and the angle at which an object is thrown, and not the initial vertical and horizontal velocities. We can use vector components to find our horizontal and vertical components of velocity. If our angle theta is to the horizontal, then our initial vertical velocity will be the initial velocity multiplied by sine theta, and our initial horizontal velocity will be the initial velocity times cos theta. So the final trick to doing projectile motion problems is to use algebra. A useful trick is to remember that the time t appears in both the vertical and horizontal equations. So if we want to link our vertical and horizontal results, one method is to make t the subject of our equations. You'll see how this works in the following examples.