The blue ball is moving more slowly. That is why it takes more time to cover the same distance as the other balls.
Its acceleration is less than the acceleration of the other balls.
Video text description for the Direct Measurement Video of Falling Through the Air
In this video, three different balls are held above the ground by ribbons: a blue foam ball with mass 3.15 grams; a small orange steel ball with mass 67.1 grams; and a large purple bowling ball with mass 5539 grams. A vertical scale, marked off in centimeters, is aligned with each ball, with the bottom of each ball at the 0-centimeter line at the beginning of the video. The video is shot at 2400 frames per second, so plays at 80 times slower than normal speed. A frame counter indicates the current frame.
At frame 130, someone cuts each ribbon at exactly the same time and the balls all start falling under the influence of gravity. At first, all the balls seem to move together, but it soon becomes clear that the blue ball takes longer to go the same distance as the others. The orange and purple balls both reach the 10-centimeter mark at around frame 472, while the blue ball takes two frames longer, reaching the 10-centimeter mark at frame 474. Later, the orange and purple balls both reach the 90-centimeter mark at around frame 1157, while the blue ball takes all the way until frame 1181 to reach 90 centimeters.
What statement best describes the relationship between the magnitudes of the accelerations of the balls? Select the best answer from the choices provided.
A. The blue ball and the orange ball appear to have the same acceleration; the purple ball has a smaller acceleration.
B. All three balls appear to have the same acceleration
C. The purple ball and the orange ball appear to have the same acceleration; the blue ball has a greater acceleration.
D. The purple ball and the orange ball appear to have the same acceleration; the blue ball has a smaller acceleration.
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Dynamics with Resistive Forces concept. If you need more Dynamics with Resistive Forces practice, you can also practice Dynamics with Resistive Forces practice problems.