When a light wave enters into a medium of different optical density, Question 3 options: 1) its speed and frequency change. 2) its speed and wavelength change. 3) its frequency and wavelength change. 4) its speed, frequency, and wavelength change.

The graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

How does the kinetic energy of a charge change as the charge moves under the effect of an electric field from higher potential to lower potential? a.the kinetic energy increases.b.the kinetic energy decreases.c.the kinetic energy remains the same.d.the kinetic energy is always zero.