A printer has a power of 100 W. It takes 30 seconds to print out a document. How much energy will it have used?

How will each of the following changes in demand and/or supply affect equilibrium price and equilibrium quantity in a competitive market; that is, do price and quantity increase or decrease, or are the answers indeterminate because they depend on the magnitudes of the shifts?

True or false: the revolution of the earth creates day and night as it rotates around the sun

What is the mass of the same rock on the earth