A contact lens is made of plastic with an index of refraction of 1.45. The lens has an outer radius of curvature of 1.92 cm and an inner radius of curvature of 2.40 cm. What is the focal length of the lens

Which seasons are the northern and southern hemispheres experiencing in the image? it is summer in both the northern and southern hemispheres. it is summer in the northern hemisphere and winter in the southern hemisphere. it is winter in both the northern and southern hemispheres. it is winter in the northern hemisphere and summer in the southern hemisphere.

Astudent is performing an experiment comparing sound and light waves. the student gathers the following data. what conclusion does the student most likely make based on this data? light waves always travel the same speed; however, the speed of sound is determined by the medium that it travels through. all sound waves always have the same energy, so the temperature of the medium does not affect wave speed. light needs to vibrate particles, so it travels fastest in tightly packed solids, while sound does not need a medium, so it travels fastest in a gas. tightly packed particles in solids slow down the light waves; however, sound waves make particles bounce into each other, so they travel faster in solids.

It is really hard for me right know