One of the recent Farmers Insurance commercials featuring the Farmers Insurance University shows a professor and students considering hypothetical trajectories drawn on a blackboard of a cow sent flying by a tornado. Here is a picture.
As physics students with knowledge of projectile motion, you are equipped with the tools to assess the accuracy of this drawing. Take some time to study the picture and make a list of things that are correct and things that are incorrect. I’ve made my own list. It is hidden in the space below this paragraph but will be highlighted if you use your cursor to select it.
Correct:
1) The cow follows a parabolic path, consistent with projectile motion.
2) The cow travels farther and higher (and thus, although it isn’t stated, stays in the air for a longer time) as the initial velocity increases.
Incorrect:
1) The units for distance are m not m/s as is shown for the middle trajectory. The rest of the units are correct.
2) Assuming negligible air resistance, the horizontal ranges are incorrect. My calculations using the horizontal range equation, R = (v02/g) sin(2θ), yield s = 116 m, 127 m, and 151 m for v0 = 42 m/s, 44 m/s, and 48 m/s, respectively.