Which of the following is a primary source?

Astone is dropped with no initial velocity from the top of a cliff and hits the ground a time of 3.9 s later. what is the height of the cliff, in units of meters? you may assume that air resistance is negligible. give the answer as a positive number question 15 a figure skater is rotating at a rate of 200 revolutions per minute. what is the angular speed, in units of rad/s? 200 o 20.9 12000 o 3.33

However, had it been a real sound, the sound's pitch would have been increased by the doppler effect, since the falcon was moving the source of the sound. perpendicular to away from towards at the same speed as

What are similarities and differences between refraction, reflection, diffraction and absorption?