If two electrically charged objects repel one another, which of the statements must be true?
a.
one object has more electrons and the other has more protons.
b.
the objects do not have strong electrical fields.
c.
the two objects have the same electric charge.
d.
electrons will flow from one object to the other when they touch each other.

In the 1980's, congress authorized the u.s. department of energy to build the wipp facility in the chicuahuan desert in new mexico. what is the purpose of wipp?

An object is 10. cm from the mirror, its height is 3.0 cm, and the focal length is 2.0 cm. what is the image height? (indicate the object orientation by including the + or - sign with the answer.) hi = cm +1.33 -1.33 +0.75 -0.75

Which of the following are properties of mechanical waves? check all that apply ⭕️ particles of the medium move back and fourth, but do not move with the wave. ⭕️ the particles of the medium always move parallel to the wave motion. ⭕️ wave motion begins with a disturbance in the medium. ⭕️ waves transport energy from a source outward, away from the source.