7. In which of the following situations is the Doppler effect absent? -Neither the source nor the observer is moving relative to one another.
-The source is moving away from the observer
-The observer is moving toward the source.
-The source and the observer are moving towards each other.

State one advantage and one disadvantage of using a plane mirrior as a driving mirrior

Awoman holds a book by placing it between her hands such that she presses at right angles to the front and back covers. the book has a mass of m = 1.8 kg and the coefficient of static friction between her hand and the book is μs = 0.67. no attempt 50% part (a) what is the weight of the book, fgb in newtons?

The ph is the a.independent variable b.the dependent variable c.control group