Your teacher burns a piece of steel wool in class, demonstrating the chemical property, flammability. You are curious to see what other things can demonstrate chemical properties. Which of these does not demonstrate a chemical change?

The magnitude of the poynting vector of a planar electromagnetic wave has an average value of 0.939 w/m2 . the wave is incident upon a rectangular area, 1.5 m by 2.0 m, at right angles. how much total electromagnetic energy falls on the area during 1.0 minute

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

Tafari worked one summer on a ship that set weather buoys in the ocean. he watched how one of the buoys moved in the water. describe which parts of the wave would cause the buoy to bob up and down. which wave property determined how fast the buoys bobbed in the water? he observed that when the wind blew harder, the ocean waves were larger, and the buoys moved away from the ship. what effect, if any, did the waves have on how far the buoys moved? explain your answer.