A 0.3-m-tall real object is located on the left side of a converging lens. An image is formed on the right side of the lens. If the image is 1.5 m tall, and the object to image distance is 5 m, what is the focal length of the lens? O 0.3 m O 0.5 m O 1.5 m O 1.1 m O 0.7 m O 2 mA real object is 2 cm tall. The object is placed on the left side of a converging lens with a focal length of 8 cm. The object forms an upright image by the lens. If the image is 20 cm away from the lens, what is the height of the image? Express the answer as a positive quantity. O 15 cm 12 cm O 9 cm O 7 cm O 20 cm 33 cmYou combine lens A and lens B by placing them in contact so that their axes coincide, forming what is called a compound lens. The focal length of lens A is 10 cm; the focal length of lens B is unknown. When a 5-cm- tall real object is placed at 10 cm from the compound lens, an upright image with a height of 8 cm is formed. What is the focal length of lens B? O -8 cm O 24 cm 12 cm 8 cm O -16 cm O -32 cmThe near point of a person's eye is 25 cm. The distance from the cornea-lens system to the retina is 2 cm. If the eye's power of accommodation is 3 D. What is the furthest object the person can see clearly? O 40 cm O 14 cm 88 cm 250 cm 100 cm 68 cmRu-106 can be used to treat melanoma in the eye. This isotope decays by B emission with a half-life of 373 days. Suppose a fresh sample contains 6x10 nuclei of Ru-106. What is the decay rate of the sample after 700 days. 86 Bq 240 Bq O 4 Bq 180 Bq 449 Bq 35 B