The cosmic redshift is a form of
a. galaxy contraction
b. the doppler effect
c. the steady-state theory
d. cosmic microwave background radiation

Quantum mechanics applies to subatomic, atomic, nanometer-size, and micrometer-size systems. nanometer, micrometer, and kilometer-size systems. atomic, nanometer-size, and micrometer-size systems. subatomic, atomic, and nanometer-size systems.

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space.b. we'll know it immediately because it will be brighter than the full moon in the sky.c. we won't know about it until 600 years from now.d. none of the above.

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up