Wavelength of light or sound depends on the position of the observer

Which of the following is an example of units for speed

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.

If the ama of the inclined plane below is 2, calculate the ima and efficiency. ima = efficiency =