Light is shining perpendicularly on the surface of the earth with an intensity of 680 W/m2. Assuming that all the photons in the light have the same wavelength (in vacuum) of 587 nm, determine the number of photons per second per square meter that reach the earth.

Which statement is true? a. kepler's laws apply only to the motion of earth. b. kepler's laws can be used to predict eclipses. c. kepler's laws are true for a central force that is directly proportional to distance. d. kepler's laws can be deduced from newton's laws of motion and gravity.

Convection currents are caused by differences in what two things?

Discuss the difference between thermal energy and heat. (terrance) terrance, egolf, r., congdon, donald. physical science student text, 5th edition. bju press, 2014. vitalbook file.