A Lesson in the Independence of Forward and Falling Motion of a Projectile Body
Why Mr. Klimetz Will Never Again Daydream in Physics Class
While attending a Regents Physics class on two-dimensional motion one sunny and pleasant Friday afternoon many years ago, Mr. Klimetz learned an invaluable lesson in the physical behavior of projectiles. Although usually a serious-minded and dedicated student, Mr. Klimetz's attentions on this fine day were directed entirely towards the gaggle of cheerleaders practicing in the field just outside the classroom window, and not at all towards his physics teacher where they should have been. The brilliant yet unforgiving (and incredibly observant) Professor Bustenhalter, immediately noticing young Klimetz's misdirected attentions, tried to evict the young Mr. Klimetz from his fantasyland by raising his voice several decibels. Unable to redirect his misguided pupil, Professor Bustenhalter then decided to demonstrate to the entire class the independence of forward and falling motion of projectiles by beaning the unsuspecting voyeur with a piece of chalk. As a veteran physics teacher as well as former star quarterback with the Heidelberg Hamsters, Professor Bustenhalter had a great deal of theoretical and practical experience in projectile motion. He studied his target carefully, noticing particularly that it was eye-level to him.He then seized a fresh piece of the brittle white stuff. Adopting the classic German football quarterback's stance, he then set it to flight at a precise 40 degree angle to the horizontal and with an exact speed of 22.9 m/s. Seconds later, Mr. Klimetz's reverie was rudely and irretrievably interrupted by the impact of chalk upon his cranium. "Touchdown, Herr Klimetz!" Professor Bustenhalter exclaimed, while raising his arms vertically above his shoulders. Needless to say, projectiles were on young Mr. Klimetz's mind, literally as well as figuratively, for the remainder of the class.
Based on the information provided in the foregoing narrative you are to
(A) Construct a Time-Horizontal Distance-Vertical Distance (Altitude) data table for the motion of the chalk projectile, from the time it left Professor Bustenhalter's hand to the time it landed upon Mr. Klimetz's head, in 0.5 s intervals.
(B) Plot a Horizontal Distance-Vertical Distance (Altitude) graph of the chalk's motion over the entire time of flight.
(C) Answer the following questions:
1. What was the horizontal (forward) component of projectile motion?
2. What was the vertical component of projectile motion at the instant the chalk was
released from the Professor's hand?
3. What length of time was the chalk in flight?
4. How distant was Mr. Klimetz from the Professor?
5. What was the greatest altitude the chalk achieved during flight?
6. At what time during flight was the maximum altitude achieved?
7. At what distance from the Professor was the greatest altitude achieved?