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.
Answer:
Electric field, 
Explanation:
It is given that, a proton in a particular electric field experiences an electric force whose magnitude is equal to the weight of the proton such that,
or
So, the magnitude of electric field at the location of the proton is 
. Hence, this is the required solution.
<span>All atoms of the same element have the same number of protons in the nucleus and consequently have the same atomic number. All atoms of the same neutral element have the same number of electrons as well.</span>
Answer:
Option D
2 m/s
Explanation:
The speed is given by distance/time
The complete wave has a distance of 8 m (This is the wavelength)
Time taken for complete wave is 4 s
Therefore, velocity= 8 m/ 4 s= 2 m/s
The amplitude is the distance between crest and trough hence 9 m- 6 m= 3 m
Frequency is 1/period and in this case period is 4 s hence frequency= 1/4= 0.25 Hz
Essentially, what we wanted is velocity
Average intensity of electromagnetic wave is given by
I= (speed of light*permittivity*sq. electric field)/2
Speed of light = 3x10^8 m/s
Permittivity = 8.85x10^-12
Therefore,
Electric field = sqrt (2I/ (speed of light xpermittivity)) = sqrt ((2*4.50)/(3*10^8*8.85*10^-12)) = 58.22 V/m
