PASCO SE-8747 Kinesthetics Cart KINESTHESIA-1 - Manual (Page 14)

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Kinesthetics Cart 012-05787C
Fig. 6-1: A ball is launched verti-
cally from a stationary cart
(stationary observer).
The equivalence of the two different motions is easily shown by comparing the motion detec-
tor traces of a coin toss with those of the horizontally moving cart.
If only a qualitative answer is desired this experiment can be simplified by having the student
rider simply hold on to one end of a bungee cord while the other end is either tied to the wall or
held by a student assistant. This keeps setup time at a minimum.
Experiment 6a: Independence of the
X and Y Motion of a Projectile
There is a common misconception about what will happen when a ball is launched vertically
from a moving vehicle, such as a car. The question “Where will the ball land?” is commonly
answered “Behind the car!” This notion most likely stems from the common experience that a
ball that is thrown up vertically through the sunroof of a car moving forward at moderate speed
will indeed land behind the car. Of course, air resistance is to blame.
Kinesthesia-1 easily remedies this misunderstanding. The PASCO projectile launcher
ME-6830 is mounted at the front of Kinesthesia-1 with a C-clamp. The launcher is oriented
vertically and the launcher is controlled by the student rider.
First, the small ball is launched vertically while Kinesthesia-1
and the rider activating the launcher are at rest (e.g. Fig. 6-1). With
no surprise, the ball returns fairly close to its point of origin. (If the
launcher is perfectly vertical, the ball will hit the muzzle of the
launcher.)
Fig. 6-2: The PASCO Projectile Launcher ME-6830 is mounted on
the Kinesthetics Cart with a C-clamp.