The 21-cm line can be used not just to find out where hydrogen is located in the sky, but also to determine how fast it is moving toward or away from us. describe how this might work.

What is the type of the reaction below? bacl2 + h2so4 → 2 hci + baso4 double replacement synthesis single replacement decomposition

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?

Arocket starts from rest and moves upward from the surface of the earth. for the first 10.0 s of its motion, the vertical acceleration of the rocket is given by ay = 12.80 m/s32t, where the +y-direction is upward. (a) what is the height of the rocket above the surface of the earth at t = 10.0 s? b) what is the speed of the rocket when it is 325 m above the surface of the earth?