What type of system allows matter and energy to enter and exit?
O A. Connected
ов. Open
O c. Closed
O
D. Isolated

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 of the choices below is one of the primary gases found in the atmosphere? a. helium b. carbon dioxide c. nitrogen d. argon

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?