140 likes | 213 Views
Mirrors. Recall: images formed by curved mirrors depend on position of image Images could be: Real or virtual Upright or inverted Smaller or larger OR no image (if object at F). Images – Concave Mirror. F. C. Images – Convex Mirror. F. C. Sign Conventions:.
E N D
Recall: images formed by curved mirrors depend on position of image • Images could be: • Real or virtual • Upright or inverted • Smaller or larger • OR no image (if object at F)
Sign Conventions: • All distances are measured from vertex: • In front = positive • Behind = negative • Focal length: • Positive for concave mirrors • Negative for convex mirrors • Distance: • di & dopositive if image & object are on reflecting side of mirror (i.e. real) • di & do negative if image or object is behind the mirror (i.e. image virtual)
Sign Conventions: • Height: • Positive for upright objects or images • Negative for inverted objects or images • Magnification: • Positive for upright images • Negative for inverted images
Ex #1 A 4cm tall object is located 30cm from a concave mirror with a focal length of 5cm. How tall is the image? Real Inverted
Ex #2 A convex mirror with a focal length of -5cm produces an image of an object located 15cm from the mirror. What is the magnification? Behind mirror Upright Smaller Virtual
Ex #3 A 1.5cm high diamond ring is placed 20cm in front of a concave mirror whose radius of curvature is 30cm. What is the size of the image? Real Inverted
Ex #4 An object is placed 10m in front of a curved mirror. A virtual image is formed 19.6cm from the mirror. What type of mirror was used? Diverging Mirror Virtual
Ex #5 Alex places a 5cm tall candle 30cm in front of a mirror that has a focal length of -50cm. What is the magnification?
Ex #6 Matt is manipulating a concave mirror that has a focal length of 10cm. His physics teacher tells him that the difference between do & di if 15cm and that the image in larger than the object & has a negative magnification. Where should Matt place the object to obtain the desired image? A) do= 15cm & di = 30cm A B) do= 30cm & di = 15cm C) do= 5cm & di = -10cm D) do= 10cm & di = -5cm