Can someone plz answer this for me..

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 textbook weighs 19.6 newtons on venus,what is the strength of gravity on venus?

Which of the following are appropriate acceleration units?