2019 #5 Free Response Question - AP Physics 1 - Exam Solution

The video tutorial covers question #5 from the 2019 AP Physics One exam, focusing on a tuning fork vibrating at 512 Hz near a tube open at both ends. The tutorial explains how to calculate the tube's length when resonating at its fundamental frequency, graph the maximum speed of air molecules, and determine the new fundamental frequency when the tube is closed at one end and placed in a different gas. The video emphasizes understanding wave patterns, displacement nodes, and anti-nodes, and provides guidance on graphing and calculations.

What is the formula to calculate the length of the tube when it resonates at its fundamental frequency?

• Length = 2 * Speed of sound / Frequency

• Length = Speed of sound / (2 * Frequency)

• Length = Frequency / Speed of sound

• Length = Speed of sound / Frequency

In a tube open at both ends, where are the displacement anti-nodes located?

• At the center of the tube

• At both ends of the tube

• At one end of the tube

• There are no displacement anti-nodes

What does a displacement node in the middle of the tube indicate about the air molecules?

• They are moving randomly

• They are moving at maximum speed

• They are not moving at all

• They are moving at half speed

What is the significance of a curve being vertically symmetrical about X = L / 2 in the graph?

• It represents the symmetry of the standing wave

• It shows that the graph is incorrect

• It means the graph is horizontal

• It indicates a uniform speed of air molecules

What is the new fundamental frequency when the tube is closed at one end and the speed of sound is 1005 m/s?

• 512 Hz

• 340 Hz

• 1005 Hz

• 760 Hz

How does capping one end of the tube affect the standing wave pattern?

• It creates two displacement nodes

• It creates a displacement anti-node at the closed end

• It creates a displacement node at the closed end

• It does not affect the standing wave pattern

What fraction of a wavelength fits in the tube when it is closed at one end?

• One wavelength

• Three quarters of a wavelength

• Half a wavelength

• One quarter of a wavelength