An object has volume of 5cm and a mass of 20 g what is the density of the object

What is created when solids,liquids,an gases mix with one another

Which of the following are appropriate acceleration units?

The magnitude of the poynting vector of a planar electromagnetic wave has an average value of 0.939 w/m^2 . 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?