Answer:
air because their is nothing contained within the air other than all the solutions that you have listed
Explanation:
A is pulling the block straight down toward the center of the Earth, no matter what the slope of the plane may be. A is the force of gravity.
The directions of B and C both depend on the slope of the plane.
B is a force that's parallel to the plane, pulling the block UP the plane. B is the force of friction.
C is a force perpendicular to the plane, preventing the block from falling down through the plane. C is the normal force.
Answer:The answer is A,B and C
Explanation: it can be use to learn universe behavior,it is also use for the measurements of velocity of galaxy,and is can also be use to indicate,galaxy motion.
Doppler effect,measures the speed which star and galaxy are moving away from us or towards us. It shows the color of wavelength to be either red shift or blue shift.
