AP Physics 2 Unit 6 MCQ A

In a movie, an observer in outer space watches a spaceship pass. The observer hears the ship's engine roaring and sees a bright exhaust plume coming from the ship's engine. Which of the following describes what is correct and/or incorrect about the waves in this scene?

A. The light from the exhaust plume could be observed because light is an electromagnetic wave and can propagate through a vacuum. The sound from the engine could not be observed because sound is a mechanical wave and requires a medium to propagate.

Students set up an experiment to shine a ray of light from one medium with index of refraction n1n1 into another medium with index of refraction n2n2. The angle of incidence is θ1θ1 and the angle of refraction is θ2θ2. In another trial, the first material is glass (n1=1.50)(n1=1.50), and the second material has an unknown index of refraction n2n2. Several angles of incidence are used, and the corresponding angles of refraction are measured. The data are shown in the table. Which of the following refinements to the experimental procedure would improve the resulting estimate of n2n2 ?

A. The measurement for the 45 degree angle of incidence should be performed again

The figure shows an object in front of a spherical concave mirror with focal length +f. Which of the following ray diagrams shows a correct ray that could be used to sketch the image of the object?

B. (First line parallel to the focal line and once it hits the mirror it goes through the focal point)

The figure shows an object in front of a spherical concave mirror with focal length +f. Which of the following correctly describes the ratio so/si of the object distance to the image distance?

B. 0<(s0/si)<1

The figure shows three regions in a container. Regions I and III contain air. Region II could contain water, glass, or vacuum. A sound wave and a light wave both travel toward the right in region I. Which of the following predictions indicates a combination of what could be in region II so that in one case both waves eventually reach region III and in another case only the light wave reaches region III?

B. Both Waves Reach Region III: Water / Only the Light Wave Reaches Region III: Vacuum

Two students are holding either end of a rope that passes through a narrow space between the boards of a fence. One student shakes the end of the rope to create a traveling wave on the rope with amplitude 1 m1 m. The table shows the amplitude of the wave on the other side of the fence for various orientations of the original wave. What is the orientation of the fence boards?

B. Horizontal

Which of the following correctly indicates whether mechanical waves and electromagnetic waves need a medium for propagation?

B. Mechanical Waves: Need a medium to propagate / Electromagnetic Waves: Do not need a medium to propagate

A disk is attached to a spring that is suspended from the ceiling, as shown. A horizontal string is also attached between the disk and a wall. The disk is pulled downward slightly and released, and the disk oscillates up and down. As the disk oscillates, it moves the end of the string up and down, creating a repeating and periodic disturbance that propagates to the right as a wave. The disk also moves the air below it up and down, creating a repeating and periodic disturbance that propagates downward as a wave. Which of the following best characterizes the two waves formed by the oscillation of the disk?

B. The wave that propagates to the right is a transverse wave because the end of the string is displaced up and down. The wave that propagates downward is a longitudinal wave because the air is pushed up and down.

The figure shows an object in front of the mirror. Two points are indicated: the center of curvature CC and the focal point ff. Which of the following correctly describes the type of image formed and its orientation?

B. Type of Image: Real / Orientation: Inverted

Students set up an experiment to shine a ray of light from one medium with index of refraction n1n1 into another medium with index of refraction n2n2. The angle of incidence is θ1θ1 and the angle of refraction is θ2θ2. In one trial, the first medium is air (n1=1.00)(n1=1.00), the angle of incidence is θ1=30°θ1=30°, and the angle of refraction is θ2=15°θ2=15°. What is n2n2 ?

C. 1.93

The graph above shows the electric field EE of an electromagnetic wave as a function of time tt at a particular point in space. Which of the following equations, where all quantities are assumed to have units consistent with the graph, best represents the graph?

C. E = 12cos(2(pi)t/20)

The students are asked to collect data that could produce a linear plot from which it is possible to determine the focal length of the lens. Which of the following quantities do the students need to measure?

C. The object distance and the image distance

A wave is traveling on a string. The string passes through a slit in a piece of cardboard. The figure shows three different orientations of the slit and the amplitude of the wave after it passes through the slit in each orientation. Which of the following is most likely the direction of the polarization of the original wave?

C. The wave is polarized at 45° to both the x-direction and the y-direction.

A teacher gives students a sunglasses lens and asks them to observe the surface of a pond on a sunny day. The students notice that the water on the surface of the pond appears brighter and then dimmer when they rotate the lens as they look through it at the pond. The teacher asks the students to explain this observation. Which of the following student statements provides a correct explanation?

D. "The light is linearly polarized when it is reflected off the surface of the pond, and the lens is a polarizing lens that transmits more light at certain angles."

A distant star explodes, releasing a burst of energy. Which of the following best predicts how waves carrying energy from the explosion will be perceived on Earth?

D. Only the flash of light will be perceivable from Earth.

A wave on an oscillating string is incident on a slit in a piece of cardboard. The slit is aligned vertically, as shown in the figure. The amplitude of the wave that approaches the slit is greater than the amplitude of the wave on the other side of the slit. Which of the following is the best conclusion about the polarization of the wave?

D. The wave is polarized at some angle between vertical and horizontal, so only a component of the amplitude will be transmitted through the slit.

A student photographs a wheat field on a windy day from two perspectives: a top view from a drone flying overhead, and a side view from where the student stands. Photographs from both views at the same moment of time are shown, with the wind direction labeled. The motion of the wheat stalks can be best described as which of the following?

A. A longitudinal wave, since the wheat tips are moving side to side, parallel to the direction of the wind