Q21DQ A tennis ball drops from rest at... [FREE SOLUTION]

91影视

University Physics with Modern Physics

Hugh D. Young, Roger A. Freedman

Physics

14th edition Edition 路 1596 pages

ISBN: 9780321973610

Chapter 1: Q21DQ (page 159)

A tennis ball drops from rest at the top of a tall glass cylinder鈥攆irst with the air pumped out of the cylinder so that there is no air resistance, and again after the air has been readmitted to the cylinder. You examine multiflash photographs of the two drops. Can you tell which photo belongs to which drop? If so, how?

Short Answer

Expert verified

The multiflash photograph of a tennis ball in a vacuum is more regular than in the air.

Step by step solution

Explanation of falling of object with and without air:

Gravity is the sole force acting on an item during a unique sort of motion called free fall. Objects that are claimed to be falling freely do not really experience much air resistance; instead, gravity is the only force acting on them as they descend. Regardless of their mass, all objects will fall with the same rate of acceleration under these circumstances.

Explanation of falling of object with and without air in a glass cylinder:

When the tennis ball falls inside a glass cylinder with a vacuum no air resistance is present for a tennis ball. The tennis ball in a vacuum falls nearly about the gravitational acceleration inside the cylinder after each jump from the bottom of the cylinder.

The tennis ball in the cylinder feels air resistance after readmission of air in the cylinder so it falls with less acceleration than gravitational acceleration. The speed of a tennis ball with air decreases after each jump from the bottom of the glass cylinder.

Method of identification of tennis ball by a multiflash photograph:

The tennis ball falls from the top and jumps from the bottom of the cylinder more frequently in a vacuum so a multiflash photograph of a tennis ball is more regular.

The frequency of falling and jumping off a tennis ball from the top and bottom of a glass cylinder with air is less than in a vacuum so a multiflash photograph of a tennis ball with air becomes blurred.