Describe what happens to a 10 kg book and a 500 kg bicycle when they are dropped from the same height and the same time in the absence of air resistance (Free-fall).

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

The three types is stress that act on earths rocks are compression, tension, and

Which process transfers heat from inside earth to its surface? convection currents in mantle pulling away of tectonic plates drawing in of tectonic plates convection currents in crust