The weight changes but the mass will stay the same.
A.cooler and hotter rock rise but do not sink.
B.hotter and cooler rock sink but do not rise.
C.hotter rock rises and cooler rock sinks.
D.cooler rock rises and hotter rock sinks.
hotter rock rises and cooler rock sinks.
Answer: Option C.
<u>Explanation:</u>
The process that happens inside the surface of earth makes the rocks inside the surface to either expand or shrink in size because of the presence of heat inside the surface.
Heat rises and as the warmer rock gets further away from the super heated center of the Earth it begins to cool off and starts to sink back toward the super heated center of the Earth where it is reheated and the whole process starts over again. That is what a convection current is.
The experimental method is usually taken to be the most scientific of all methods, the 'method of choice'. The main problem with all the non-experimental methods is lack of control over the situation. The experiment method is a means of trying to overcome this problem. The experiment is sometimes described as the cornerstone of psychology: This is partly due to the central role experiments play in many of the physical sciences and also to psychology's historical view of itself s a science. A considerable amount of psychological research uses the experimental method. <span />
Answer:
C. f = 440 Hz
Explanation:
- In any wave, there is a fixed relationship between the wavelength (distance between two sucesive crests), the frequency (number of cycles per unit time) and the perturbation speed, as follows:

where v = speed of the wave
λ = wavelength
f = frequency
- Replacing by the givens in (1) and solving for f, we have:

You get a repetative <span>increase in velocity </span>