I believe it is D. Earth spinning on it's axis.
Answer:

Explanation:
From the Question We are told that
Initial Force 
Final Force 
Distance between the front and rear wheels \triangle x=3.20 m
Since

Therefore


Generally the equation for The center of mass is at x_2 is mathematically
given by




Answer:
statement - 'The work done by friction is equal to the sum of the work done by the gravity and the initial push' is correct.
Explanation:
The statement ''The work done by friction is equal to the sum of the work done by the gravity and the initial push" is correct.
The above statement is correct because, the initial push will tend to slide down the block thus the work done by the initial push will be in the downward direction. Also, the gravity always acts in the downward direction. thus, the work done done by the gravity will also be in the downward direction
here, the downward direction signifies the downward motion parallel to the inclined plane.
Now we know that the work done by the friction is against the direction of motion. Thus, the friction force will tend to move the block up parallel to the inclined plane.
Hence, for the block to stop sliding the the above statement should be true.
Renewable energy
<u>Advantages :-</u>
1. Easily regenerate
2. Boost economic growth
3. Easily available
4. Support environment
5. Low maintenance cost
<u>Disadvantages :-</u>
1. Weather dependency
2. High installation cost
3. Noise caused by wind energy
4. Fluctuation problem (solar)
5. Intermittency issue (wind)
Non-renewable energy
<u>Advantages :-</u>
1. Concentrated energy source
2. Reliable energy source
3. Can be built anywhere
4. No radioactive waste
<u>Disadvantages :-</u>
1. Produces greenhouse gases
2. Contributes to global warming
3. Produces acid rain
4. Harmful to environment when they are burnt
<em>I hope this helps.....</em>
Answer:
The wavelength of the visible line in the hydrogen spectrum is 434 nm.
Explanation:
It is given that, the wavelength of the visible line in the hydrogen spectrum that corresponds to n₂ = 5 in the Balmer equation.
For Balmer series, the wave number is given by :

R is the Rydberg's constant
For Balmer series, n₁ = 2. So,


or

So, the wavelength of the visible line in the hydrogen spectrum is 434 nm. Hence, this is the required solution.