Unit 4: Continued

(Source: Flickr: http://farm4.static.flickr.com/3180/3087734516_dcec92a486.jpg)

To add to the complexity of 2D kinematics, they decided to teach us trigonometry. We learned SOHCAHTOA in geometry last year, but it was refreshing to review it again. SOH stands for sine = opposite over hypotenuse, while CAH stands for cosine = adjacent over hypotenuse, and TOA stands for tangent = opposite over adjacent.

We use when solving for sides of a right triangle using given angle and side measures. The diagonal on the graph that you are using serves as the hypotenuse of the triangle that you will draw. You need to find the horizontal and vertical velocities in order to find the amount of time the projectile was in the air and the horizontal rage that the object flew.

Let's say that someone got a paintball gun and is practicing using it. They shoot a paintball with a velocity of 35 m/s at an angle of 50 degrees. To calculate the initial horizontal velocity, use SOH. (Look at picture for a visual aid)

To calculate the horizontal velocity, take the sine of 40 (opposite) and multiply it by 35 (the hypotenuse) to get 22.49 m/s for horizonal velocity.

If you wanted to find out how long the paintball was in the air, you would have to set up a T table. Use your given data and that data that you solved for into the graph. Be careful not to use 35 m/s (the diagonal velocity) as one of your velocities in the table.

Use the equation V=Vo + at to get your time value. Plug in data. (see picture)

Now, use your time value to see how far your paintball went!