If dropped separately, the paper flies about. If dropped with the paper on top of the book, they fall at the same rate. Why?

Explain why the aperture of the spherical mirror should be small compared to the radius of curvature of the mirror.

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.

Which of the following are guidelines to follow for obtaining accurate observations