What are two main types of exercise???

How does the amount of energy required to hold each proton and neutron in the nucleus compare to the energy released when they are removed?

Using a caesar cypher with an offset of three characters (a -> d, b -> e, z -> c), what would be the correct cypher text for the plain text "attack at dawn"?

By examining a wave’s pattern after it interacts with a barrier or gap, measurements can be made to better understand certain wave phenomena. what is a broad question you can answer by doing this experiment?