(a) A boy with a mouth 5 cm wide stands 2 m away from a plane mirror. Where is his image and how wide is the image of his mouth?(b) The boy walks towards the mirror at a speed of 1 m/s. At what speed does his image approach him?
(a) The image will form 2m behind the mirror and 5 cm wide. The reason being, the characteristic of plane mirror, which states that a plane mirror forms an image of the same size as the object, and at the same distance behind the mirror as that of the object from the mirror.
(b) When the boy walks towards the mirror at a speed of 1 m/s, his image will also appear to move towards the mirror at the same speed of 1 m/s. So, the speed at which his image approaches him will be 2 m/s + 2 m/s = 4 m/s.
Explanation with the image is posted for reference only.
Characteristics of the image formed by a plane mirror are virtual, erect (upright), of the same size, laterally inverted and at the same distance.
Plane mirrors are used in kaleidoscopes, shaving mirrors, dentists' mirror, torch lights, etc.
Related Articles
- An observer moves towards a stationary plane mirror at a speed of 4m/s speed, the speed at which his image moves towards him is?
- The rearview mirror of a car is a plane mirror. A driver is reversing his car at a speed of 2 m/s. The driver sees in his rearview mirror the image of a truck parked behind his car. The speed at which the image of the truck appears to approach the driver will be(I) 1 m/s (ii) 2 m/s (iii) 4 m/s (iv) 8 m/s\n27771"
- David is observing his image in a plane mirror. The distance between the mirror and his image is 4 m. If he moves 1 m towards the mirror, then the distance between David and his image will be$(i).\ 3\ m$ $(ii).\ 5\ m$$(iii).\ 6\ m$ $(iv).\ 8\ m$
- A man stands 10 m in front of a large plane mirror. How far must he walk before he is 5 m away from his image?
- A man sits in an optician's chair looking into a plane mirror which is 2 m away from him and views the image of a chart which faces the mirror and is 50 cm behind his head. How far away from his eyes does the chart appear to be?
- A boy weighing $40\ kg$ makes a high jump of $1.5\ m$. (i) What is his kinetic energy at the highest point? (ii) What is his potential energy at the highest point? $(g=10\ m/s^2)$.
- A large concave mirror has a radius of curvature of 1.5 m. A person stands 10 m in front of the mirror. Where is the person's image?
- If an object is placed at a distance of 0.5 m in front of a plane mirror, the distance between the object and the image formed by the mirror will be$(a)$. 2 m$(b)$. 1 m$(c)$. 0.5 m$(d)$. 0.25 m
- A convex mirror used as a rear-view mirror in a car has a radius of curvature of 3 m. If a bus is located at a distance of 5 m from this mirror, find the position of image. What is the nature of the image?
- The image formed by a spherical mirror is real, inverted and is of magnification –2. If the image is at a distance of 30 cm from the mirror, where is the object placed? Find the focal length of the mirror. List two characteristics of the image formed if the object is moved 10 cm towards the mirror.
- Two big mirrors A and B are fitted side by side on a wall. A man is standing at such a distance from the wall that he can see the erect image of his face in both the mirrors. When the man starts walking towards the mirrors, he finds that the size of his face in mirror A goes on increasing but that in mirror B remains the same.(a) mirror A is concave and mirror B is convex(b) mirror A is plane and mirror B is concave(c) mirror A is concave and mirror B is plane(d) mirror A is convex and mirror B is concave
- A boy is standing in front of and close to a special mirror. He finds the image of his head bigger than normal, the middle part of his body of the same size, and his legs smaller than normal. The special mirror is made up of three types of mirrors in the following order from top downwards:Convex, Plane, ConcavePlane, Convex, ConcaveConcave, Plane, ConvexConvex, Concave, Plane
- Where is the image when you look at something in a mirror?
- A converging mirror forms a real image of height 4 cm of an object of height 1 cm placed 20 cm away from the mirror:(i) Calculate the image distance.(ii) What is the focal length of the mirror?
- $(a)$. Find out the position of the image of an object situated at A in the plane mirror (Fig. 16.21).$(b)$. Can Paheli at B see this image?$(c)$. Can Boojho at C see this image?$(d)$. When Paheli moves from B to C, where does the image of A move?"
Kickstart Your Career
Get certified by completing the course
Get Started
Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies