How do scientists use the doppler effect to understand the universe?

a. to determine motion of objects.

b. to determine the ages of planets

c. to determine the planet.

what does a blue shift in the light from stars indicate?

a. the stars are moving randomly

b. the stars are stationary

c. the stars are moving closer (towards each other)

For the First answer, It would be "A"

The for the next one the answer is "C"

I hope this helps. :)

The correct answer is A.

The correct answer is C.

Explanation:

Doppler effect is the phenomenon in which there is an apparent change in the frequency of the wave when there is a relative motion between the observer and the source.

Scientists use the Doppler effect to understand the universe by determining the motion of the object.

Therefore, the correct answer is A.

Light changes as the object in space (such as star) moves away from us then the light is shifted to red end. In this case, the light is shifted to longer wavelength.

Light changes as the object in space (such as star) moves towards us then the light is shifted to blue end. In this case, the light is shifted to shorter wavelength.

In the given problem, the when the stars are moving towards each other then the blue shift in the light will occur.

Therefore, the correct option is C.

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.