Amaterial has a net electric charge because it

a. has friction between electrons and protons

b. has the ability to create static discharge

c. has an excess or shortage of electrons.

d. has a large atomic nucleus

Imagine you are standing in the antarctic during the southern hemisphere summer. the sky is clear and blue. there are no clouds in the sky. your shadow is cast on the icy ground. what is the color of the shadow?

Observations show that interstellar clouds can have almost any shape and

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?