波的性質、光與聲：練習題

A ray of light travels from air into a rectangular glass block at an angle. Which of the following statements correctly describes the behavior of the light ray as it enters the glass?

A ray of light hits a flat mirror at an angle of incidence of \(30^{\circ}\). According to the law of reflection, what is the angle of reflection?

A ray of monochromatic light is incident on the hypotenuse of a right-angled isosceles glass prism as shown in the diagram. The refractive index of the glass is \(n = 1.52\). If the ray strikes the internal surface at an angle of incidence of \(45^{\circ}\), what is the subsequent path of the light ray?

A student stands between two parallel vertical cliffs that are separated by a distance \(D\). The student is closer to one cliff than the other. When the student claps their hands, they hear the first echo after \(1.2\text{ s}\) and the second echo after \(1.8\text{ s}\). Given that the speed of sound in air is \(340\text{ m/s}\), calculate the distance \(D\) between the two cliffs.

An object is placed at a distance of \(15\text{ cm}\) from a thin converging lens with a focal length of \(10\text{ cm}\). Which of the following best describes the nature and position of the image formed?

A student is standing in front of a tall vertical wall and claps their hands. The student hears the echo exactly 0.4 seconds later. The speed of sound in air is given as \(340\text{ m/s}\).

(a) Explain why an echo is heard after a short delay.
(b) Calculate the distance between the student and the wall.

A light ray travels from air into a rectangular glass block at an angle of incidence of \(45^{\circ}\). The refractive index of the glass is 1.50.

(a) Calculate the angle of refraction inside the glass block to one decimal place.
(b) Draw a ray diagram showing the incident ray, the refracted ray, and the emergent ray as it leaves the other side of the parallel glass block. Label the normal and the angles involved.
(c) Describe how the speed of light changes as it enters the glass from the air.