Answer:
f'=5.58kHz
Explanation:
This is an example of the Doppler effect, the formula is:
Where f is the actual frequency, 
is the observed frequency, 
is the velocity of the sound waves, 
the velocity of the observer (which is negative if the observer is moving away from the source) and 
the velocity of the source (which is negative if is moving towards the observer). For this problem:
Answer:
3.43 m/s^2
Explanation:
Force is equal to mass times acceleration. (F=ma). You can use inverse operations to get the formula for acceleration, which is acceleration is equal to force divided by mass. (a=F/m). Since there are two forces here, the force friction (55 N), and the force applied (175 N), we must solve for the net force. To solve for the net force, you take the applied force (175 N) and subtract the frictional force from it (55 N). Thus, the net force is 120 N. With this done, we can now solve for our acceleration.
Using the equation for acceleration, we take the force and divide it by mass.
120/35
Answer: 3.43* m/s^2**
*Note: This is rounded to the nearest hundredth, the full answer is: 3.42857143
**Note: In case you're confused, this is meters per second squared.
Answer: It is both B and D
Select all that apply.
At night, thermal energy moves _____.
from space to the atmosphere
from the land to the atmosphere
from the atmosphere to the land
from the atmosphere to space
