they are added vectorially. If htere is a resultant force, the thing acclerates. If they vectorially add to zero, thing doesn't move
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.
Some are fuel,chemicals,plastics,asphalt,and road oil.