13. Five parallel rays of light are incident onto a concave reflective surface. They are reflected and pass through a focal point 8.4 cm away along the principal axis. What is the radius of curvature for the concave surface

What is the approximate amplitude of this wave a.10 seconds b.15 centimeters c.30 centimeters d.15 seconds

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Which additional product balances the reaction h2so4 + 2naoh → na2so4 + 2h2o 2oh h2o2 h3o