PHYSICS: So you ready for that test tomorrow? Since the help session isn’t until tomorrow morning, I thought I’d go ahead and post a couple of old reviews on the homework and worksheet problems (2 different vodcasts from last year). Don’t forget what you should do to start – Draw a picture, write what you know, resolve the resultant velocity into vertical and horizontal if you need to, and find formulas that fit (because it will hardly ever be solved with just one) and go for it!!
If you are talking angular projectiles, the resultant velocity is actually made up of two things – horizontal velocity and vertical velocity. The horizontal velocity never changes, the vertical velocity has a different direction going up and coming down, but it has the same speed at equal levels. If you’re talking horizontal projectiles, the resultant velocity is the same as the horizontal velocity of the gun, because that’s the only kind of initial velocity it has! Relative motion is even easier – just use the Pythagorean theorem and tangent, and use horizontal to find horizontal and vertical to find vertical. Good luck!!