Avehicle traveling away from an observer has a malfunctioning horn that sounds continuously.
if the vehicle travels with a constant positive acceleration away from the observer, which of the following represents the magnitude of the change in frequency experienced by the observer over time?

a. δf is constant over time
b. δf increases linearly over time
c. δf increases exponentially over time
d. δf decreases linearly over time

30) B; To analyze this question, recall the equation for Doppler, Δf/f = v/c. This demonstrates that the change in frequency is directly proportional to the relative velocity. If the acceleration is constant, the velocity is changing at a constant rate, so anything directly proportional to that must be changing at a constant rate. Because no squares or roots are involved, it must be linear, not exponential, making B the best answer.

Explanation:

and 1and 1

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.