Associated reading: Sections 4.1 and 4.2.

This will be your introduction to the two-dimensional motion of projectiles. A projectile is an object that has a horizontal motion as well as a vertical motion that is influenced by gravity. The stroboscopic photo to the right shows a poker chip (red) and a plastic popper toy projected off of a table top. When the popper sprang upward, it flipped the poker chip, giving it both vertical and horizontal components of velocity. You can tell that the popper has the greater vertical velocity component, because the vertical distance between images is greater and it goes higher.

The video clips below stress the independence of the horizontal and vertical motions of projectiles. After you watch the videos, there's an assessment to do. The assessment includes some fairly simple questions that anyone who watched the video could answer correctly.  However, there are several questions that check whether you listened closely to the explanation of the key phenomenon being demonstrated. You can always take another look at the videos or read the scripts for details.

As a reminder, the streamed format is universal and will even play on smart phones. The other formats can be downloaded to your computer if you want that convenience.