A 2 m tall lamp is placed 1.25 m from a double convex lens that has a focal length of 0.75 cm. What is the image height of the lamp?

Question

Quizplus · Accepted Answer

To answer this question, the lens equation needs to be used, which has the following formula: 1/f = 1/d_o + 1/d_i Where: f is the focal length d_o is the object distance d_iis the image distance. Solve for the image height: 1/f = 1/d_o + 1/d_i 1/0.75 m = 1/1.25 m + 1/d_i 1.33 m^-1- 0.8 m^-1= 1/d_i 0.53 m^-1 = 1/d_i d_i=1.89 m Then, the magnification equation needs to be used, which has the following formula: h_i/ h_o = - d_i/d_o where h_iis the image height, h_ois the object height, d_ois the object distance, and d_iis the image distance. h_i/ 2 m = - 1.89 m /1 m h_i= - 3.78 m

A 2 M Tall Lamp Is Placed 1