Answer:
1. There are four main types of earthquake waves: P-waves and S-waves (which are body waves), and Rayleigh waves and Love waves (which are surface waves).
2. potential energy
3. Newton's second law of motion is F = ma, or force is equal to mass times acceleration.
4. For a lens it is called refraction. Refraction is the change in the direction of light when passing from one transparent medium to another.
5. The formula for density is the mass of an object divided by its volume. In equation form, that's d = m/v , where d is the density, m is the mass and v is the volume of the object.
