Answer:
B. A large number of atoms move from one place to another
Explanation:
Convection is heat transfer by the movement of atoms of a substance from one region to another across a temperature gradient. Since atoms of solids are rigidly held in place, convection only occurs in liquids and gases since they flow.
Convection occurs when the temperature of one region of a fluid (liquid or gas) is higher than its other region. There is thus a mass movement of atoms from one region to the other due to a temperature difference. The atoms will continue to move to the region of lower temperature until the temperature of both regions are the same at an equilibrium temperature.
Answer:
Time = 1.36s
Explanation:
coefficient of kinetic friction = μk
μk = F/N = F / mg
where m = mass of the body
g = acceleration due to gravity.
Doubling the force on the box we have,
μk = 2ma/mg
hence μk = 0.15/2 = 0.075
To determine the time it takes to reach a velocity of 2m/s from 1m/s .
From Newton law of motion,
v = u + a*t
for a deceleration of a = μk x g
2m/s = 1m/s + 0.075 x 9.8m/s² x t
t = (2m/s - 1m/s)/0.735m/s²
t = 1.36 seconds..
it will take the 1.36s for the crate to double to 2.0m/s
A). Scale.
You CAN measure volume with all the following except a scale.
Answer:
Radio waves have a wavelength between and
While,
X rays have a wavelength between 1m and 10km.
=> It is one of the condition of diffraction that the obstacle (coming in the way) must be comparable with the size of the wavelength.
=> This shows, that radio waves have a wavelength which is comparable with the size of buildings and can really easily diffract through it
=> While, X-rays are big enough to diffract through the wall.
So, if an X-ray technician stands behind a wall during the use of her machine, she will remain safe.
the answer is a= 16m/s2
you can use the formula f=m*a to solve this bb :)