The sun is about 150 million km from earth. how long does it take light from the sun to reach earth? (speed of light is 3x10^8m/s)

What are the applications of electromagnetic waves

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.

Hydrogen and helium are both members of?