Final answer:
In Terri's experiment, the dependent variable is the time it takes for balls of different sizes to travel specific distances. This experiment observes the effect of ball size on instantaneous and average speed. Factors like human reaction time and release technique may cause discrepancies in the results.
Step-by-step explanation:
Terri is conducting an experiment to see if the size of a ball affects its instantaneous and average speed. In her experiment, the dependent variable is the time it takes for each different-sized ball (tennis ball, softball, and basketball) to roll a specific distance. The time is dependent because it is what Terri is measuring in response to changing the size of the ball, which is the independent variable. Her experiment’s goal is to find out if there are any changes in the balls' speeds due to their sizes.
To accurately capture the instantaneous speed, Terri could measure the speed at a fixed point after the balls are released, while the average speed could be determined by dividing the total distance traveled by the total time taken from when a ball is released until it comes to a stop.
Relevant concepts to Terri's experiment include possible causes of discrepancies in the timing, which may be attributed to human reaction time variability when starting and stopping the stopwatch or slight differences in the way each ball is released. Such inconsistencies could impact both the instantaneous and average speeds. Additionally, the role of friction, air resistance, and ball mass in determining the balls’ acceleration should be considered.