A farsighted woman breaks her current eyeglasses and is using an old pair whose refractive power is 1.720 diopters. Since these eyeglasses do not completely correct her vision, she must hold a newpaper 42.00 cm from her eyes in order to read it. She wears the eyeglasses 2.10 cm from her eyes. How far is her near point from her eyes?
An anatomist is viewing heart muscle cells with a microscope that has two selectable objectives with refracting powers of 100 and 300diopters. When she uses the 100 diopter objective, the image of a cell subtends an angle of 3 multiplied by 10-3 rad with the eye. What angle is subtended when she uses the 300 diopter objective?
A microscope for viewing blood cells has an objective with a focal length of 0.50 cm and an eyepiece with a focal length of 2.5 cm. The distance between the objective and eyepiece is 14.0 cm. If a blood cell subtends an angle of 2.1 multiplied by 10-5 rad when viewed with the naked eye at a near point of 27.0 cm, what angle (magnitude only) does it subtend when viewed through the microscope?