The pitch of the siren of a moving fire truck changes from high to low as the fire truck passesby. what property of sound wave changes as the fire truck goes by?

Pls! plant cells and animal cells were observed under a microscope. the characteristics of two cells are listed below. cell p: does not capture sunlight cell q: has cytoplasm but no chloroplast which statement about the two cells is correct? cell q also has a cell wall. cell q also has large vacuole. cell p also has a large vacuole. cell p also has a cell membrane.

How would you reduce the volume of gas

Which of these expressions are correct variations of the combined gas law? p1v1t2 = p2v2t1 both