Which describes how to compare the energy of two different waves?

a. measure their frequencies

b. measure their periods

c. measure their amplitudes

d. measure their wavelengths

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

What is a subatomic particle with a negative charge and very little mass?

The items in the following list are all units of matter. which is the smallest unit that retains the properties of the matter? a.) atom b.) compound c.) electron d.) element