Assuming: f = 10 cm C = 20 cm p = 12 cm q = 60 cm h = 5 cm h = - 25 cm M = -5

Transcription

1 Object Distance greater than C Object Distance at C Assuming: f = 10 cm C = 20 cm p = 25 cm q = h = 5 cm h = cm M = Assuming: f = 10 cm C = 20 cm p = 20 cm q = 20 cm h = 5 cm h = -5 cm M = -1 Concave Mirrors 9 Concave Mirrors 10 Object Distance between C and F Object Distance between C and F Assuming: f = 10 cm C = 20 cm p = 16 cm q = 26.6 cm h = 5 cm h = cm M = Assuming: f = 10 cm C = 20 cm p = 12 cm q = 60 cm h = 5 cm h = - 25 cm M = -5 Concave Mirrors 11 Concave Mirrors 12 1

2 Object Distance at F Object Distance less than F Assuming: f = 10 cm C = 20 cm p = 10 cm q = doesn t exist h = 5 cm h = N/A M = N/A Assuming: f = 10 cm C = 20 cm p = 7 cm q = h = 5 cm h = cm M = 3.33 Concave Mirrors 13 Concave Mirrors 14 Object Distance greater than C Object Distance at f Assuming: f = -10 cm C = -20 cm p = 30 cm q = cm h = 5 cm h = 1.25 cm M =. 25 Assuming: f = -10 cm C = -20 cm p = 30 cm q = -5 cm h = 5 cm h = 2.5 cm M =.5 Convex Mirrors 15 Convex Mirrors 16 2

3 Name: Date: Section C D F Reflection I: Flat Mirror Mr. Alex Rawson Physics 1. If the vertical line shown below was a mirror, and the man s face would be reflected on the left side, find the point where the image of the man s mouth should appear. Draw a ray from the man s mouth to all four points listed on the mirror (the normals have been drawn for you as dotted lines); reflect the rays, and find the image point by where the extensions of the reflected rays converge. (4 pts) a. b. Hint: Remember that rays of light bounce off the mirror, and the reflected rays are extended into the mirror, where the image point appears. Listed below is an example of the image point of the man s nose. Reflected ray Extension of reflected ray r i Normal Incident ray i.

4 2. Reflect the pencil over the mirror using ray diagrams. Draw a ray, normal, reflection, and extension of the reflected ray to find the image point of both the eraser and the tip of the pencil. (4 pts) 3. A ray of light strikes a mirror at an angle of incidence of 28 o. What is the angle of reflection? (2 pts) Since the angle of incidence = angle of reflection, r = 28 o 4. If the hand featured below is 4 inches away from the mirror shown, how far away from the actual hand is the image of the hand? (2 pts) 8 inches p = 4 inches, q= 4 inches p + q = 8 inches

5 Name: Date: Section C D F Mr. Alex Rawson Physics Reflection II: Ray Diagrams, Real Images 1. For the following images, please calculate image distance, image height, and magnification. 2. The following slides illustrate an image being reflected by a curved mirror. The only element that changes is the object distance, and from that the image distance changes, as well as the image height and magnification. Certain elements are the same, such as radius of curvature and height of the object. 3. Remember the 4 rules of mirrors: i. Any ray that travels parallel to the principal axis reflects to the focal point. ii. Any ray that travels through the focal point reflects parallel to the principal axis. iii. Any ray that travels through the center reflects back to the center. iv. Any ray that strikes the mirror at point is reflected over the principal axis (the principal axis acts as the normal). 4. Rays must converge to create an image point. If rays diverge on one side of the mirror, they must converge on the other side of the mirror. This is evident when an object is within the focal point of a concave mirror, and at all distances from a convex mirror. 5. Please consult the textbook pages to ensure that your diagrams are correct. 6. Please use the Links page on The Vault for supplemental applets, diagrams, and explanations. 1

6 Object Distance greater than C Concave Mirrors 2

7 Object Distance at C Concave Mirrors 3

8 Object Distance between C and F Concave Mirrors 4

9 Object Distance between C and F Concave Mirrors 5

10 Object Distance at F Concave Mirrors 6

11 Name: Date: Section C D F Mr. Alex Rawson Physics Reflection III: Ray Diagrams, Virtual Images 1. For the following images, please calculate image distance, image height, and magnification. 2. The following slides illustrate an image being reflected by a curved mirror. The only element that changes is the object distance, and from that the image distance changes, as well as the image height and magnification. Certain elements are the same, such as radius of curvature and height of the object. 3. Remember the 4 rules of mirrors: i. Any ray that travels parallel to the principal axis reflects to the focal point. ii. Any ray that travels through the focal point reflects parallel to the principal axis. iii. Any ray that travels through the center reflects back to the center. iv. Any ray that strikes the mirror at point is reflected over the principal axis (the principal axis acts as the normal). 4. Rays must converge to create an image point. If rays diverge on one side of the mirror, they must converge on the other side of the mirror. This is evident when an object is within the focal point of a concave mirror, and at all distances from a convex mirror. 5. Please consult the textbook pages to ensure that your diagrams are correct. 6. Please use the Links page on The Vault for supplemental applets, diagrams, and explanations. 1

12 Object Distance at F Concave Mirrors 2

13 Object Distance less than F Concave Mirrors 3

14 Object Distance greater than C Convex Mirrors 4

15 Object Distance at f Convex Mirrors 5

16 Name: Date: Section C D F Reflections IV: Mirror Calculations Mr. Alex Rawson Physics 1. A 4 foot tall boy is standing 10 feet away from a concave mirror in the House of Mirrors. If the mirror has a radius of curvature of 13 feet, will his image be: a. Inverted or upright? (circle one) (1 pt) b. Maximized or minimized? (circle one) (1 pt) c. At a closer distance to the mirror than the object? Yes / No (circle one) (1 pt) d. Draw a ray diagram. Assume that the boy s feet are on the principal axis, similar to all of the diagrams we have drawn in the past. (3 pts) e. Find q, the image distance (2 pts) f. Find h, the image height (2 pts) g. Find M, the magnification (2 pts)

17 2. The child finds another concave mirror, and walks closer and closer to the mirror. a. If the child is initially very far away (beyond C), what happens to the size of his image as he approaches? (2 pts) i. Gets smaller ii. Gets larger iii. Stays the same iv. Not enough information b. If the child finds that when he stands 3 feet away, his image is upright and twice as large as he is, i. Find q, the image distance (2 pts) ii. Find R, the radius of curvature (2 pts) iii. Draw a ray diagram. (3 pts) 3. Find the image of the arrow in the convex mirror. Be sure to notice that the base of the arrow is below the principal axis; however all of our rules still apply. Find the image points of the tip of the arrow and the base of the arrow. (3 pts) a. What do you notice about the vertical alignment of the image points of the tip and base? Do the tip and the base still align vertically in the image? Yes / No (circle one) (1 pt)

18 4. Now let s take two object points that are vertically aligned in the diagram of the truck below. Find the image points of the person s head (similar to the tip of the arrow) and the bottom of the front left wheel (similar to the base of the arrow). Draw a ray diagram. (3 pts) a. b. Does the phrase OBJECTS IN MIRROR ARE CLOSER THAN THEY APPEAR sound familiar? You got it. It's printed on the side-view mirror of your car, but only on the passenger side mirror. On the driver's side of the car, car manufacturers are required to provide a flat plane mirror, however the mirror on the passenger side is required by law to have this message printed on it. Why would the federal government require this message to be printed on the passenger side mirror and not the driver s side mirror? Please write in full sentences. (2 pts) The passenger s side mirror is convex; hence the objects in the mirror are not a proportional distance away, like flat mirrors. Convex mirrors create images that are smaller than the object, while flat mirrors reflect full size images. If the viewer believed that the mirror was a flat mirror, the viewer would think that the object is farther away. Hence the warning that objects are closer than they appear. 5. What is the advantage of the convex mirror in the image below? Please write in full sentences. (2 pts) Convex mirrors give a wider range of viewing angle, thus it is advantageous when attempting to look around corners.