Exercises: Reflection and Images in Plane Mirrors
A ray of light strikes a flat bathroom mirror. The angle between the incident ray and the normal (the line perpendicular to the mirror) is $35^\circ$. State the law of…
A ray of light strikes a flat bathroom mirror. The angle between the incident ray and the normal (the line perpendicular to the mirror) is $35^\circ$. State the law of reflection and give the angle of reflection measured from the normal.
Sofia stands $2.0\ \text{m}$ in front of a plane mirror in her school's dance studio. How far behind the mirror does her image appear to be, and how far is she from her…
Sofia stands $2.0\ \text{m}$ in front of a plane mirror in her school's dance studio. How far behind the mirror does her image appear to be, and how far is she from her image?
Classify the image formed by a plane mirror by answering each question: Is it real or virtual? Is it upright or inverted? Is it larger than, smaller than, or the same…
Classify the image formed by a plane mirror by answering each question: Is it real or virtual? Is it upright or inverted? Is it larger than, smaller than, or the same size as the object?
Marcus is $1.80\ \text{m}$ tall and stands $3.0\ \text{m}$ from a vertical plane mirror. He walks toward the mirror at a constant speed of $1.2\ \text{m/s}$ for…
Marcus is $1.80\ \text{m}$ tall and stands $3.0\ \text{m}$ from a vertical plane mirror. He walks toward the mirror at a constant speed of $1.2\ \text{m/s}$ for $1.5\ \text{s}$. (a) How far is he from the mirror at the end? (b) How far is he from his image at the end? (c) At what speed does his image approach him while he walks?
A laser pointer on a lab table sends a ray toward a horizontal plane mirror lying flat on the table. The ray makes an angle of $30^\circ$ with the surface of the mirror…
A laser pointer on a lab table sends a ray toward a horizontal plane mirror lying flat on the table. The ray makes an angle of $30^\circ$ with the surface of the mirror (not with the normal). Find the angle of incidence, the angle of reflection, and the angle between the incident ray and the reflected ray.
Aaliyah holds a small arrow-shaped object $4.0\ \text{cm}$ tall, pointing up, $10\ \text{cm}$ in front of a plane mirror. Describe how to locate the image of the arrow…
Aaliyah holds a small arrow-shaped object $4.0\ \text{cm}$ tall, pointing up, $10\ \text{cm}$ in front of a plane mirror. Describe how to locate the image of the arrow tip with two rays drawn from the tip. Then state the image's height, its distance behind the mirror, and the direction it points.
Ethan is $1.70\ \text{m}$ tall, with his eyes $1.60\ \text{m}$ above the floor. He wants to see his whole body in a vertical plane mirror hung on a wall. (a) Using the…
Ethan is $1.70\ \text{m}$ tall, with his eyes $1.60\ \text{m}$ above the floor. He wants to see his whole body in a vertical plane mirror hung on a wall. (a) Using the law of reflection and ray diagrams, find the minimum height of the mirror. (b) Find how high above the floor the bottom edge of the mirror must be. (c) Ethan then steps farther back from the mirror. Does the minimum mirror height change? Justify your answer.
Two plane mirrors meet at a right angle ($90^\circ$) to form a corner. A small object sits inside the corner, $0.20\ \text{m}$ from one mirror and $0.30\ \text{m}$ from…
Two plane mirrors meet at a right angle ($90^\circ$) to form a corner. A small object sits inside the corner, $0.20\ \text{m}$ from one mirror and $0.30\ \text{m}$ from the other. Treat the mirrors as meeting along a vertical line and look at the setup from above. Using coordinates with the corner at the origin, place the mirrors along the positive $x$-axis and positive $y$-axis, so the object is at $(0.30, 0.20)$ in meters. (a) Find the coordinates of the two images formed by a single reflection. (b) Find the coordinates of the third image, formed by reflection in both mirrors. (c) Explain with a ray diagram why a person looking into the corner sees three images.