Joe lifts a 20.0 kg mass from the floor to 1.8 meters above the ground. What is the change in PE?

What happens to an isotope during radioactive decay?

Efficiency is the ratio of to for a system a)power in to power in b)power in to power out c) power out to power out d) power out to power in

Which of these statements best explains how the hydrosphere interacts with the atmosphere to affect global climate? mountains block rain clouds and cause changes in global rainfall and evaporation. humans burn fossil fuels to produce greenhouse gases which cause global warming. humans cut down trees which affects the amount of oxygen in different parts of the globe. greenhouse gases, like carbon dioxide, dissolve in oceans and prevent global warming.