Because the light colors will only work on a dark background, as dark colors will only work on a light background. If light color were on the white background not only will it be nearly impossible to read, the letters with have to be much larger for older people to read or see. Therefore, Black letters on a white background is most common. But a Black background with white letters could also work, kind of like a chalkboard.
Answer:
Answered
Explanation:
a) Two balls are at a distance of L/2 from the axis of rotation and one block at the center. ( center of rod).
therefore,
b) two balls at a distance L/4 at the from the axis and 1 ball at a distance 3L/4 from the from the axis.
=
Answer:
d) 1/32 microgram
Explanation:
First half life is the time at which the concentration of the reactant reduced to half.
Second half reaction is the time at which the remaining concentration reduced to half or the initial concentration reduced to 1/4.
Third half life is the time at which the remaining concentration reduced to half or the initial concentration reduced to 1/8.
Forth half life is the time at which the remaining concentration reduced to half or the initial concentration reduced to 1/16.
Fifth half life is the time at which the remaining concentration reduced to half or the initial concentration reduced to 1/32.
The initial mass of the sample = 1 microgram
After 5 half-lives, the mass should reduce to 1/32 of the original.
So the concentration left = 1/32 of 1 microgram = 1/32 microgram
Answer:
Electric current
Explanation:
An electric current is the rate of flow of electric charge past a point or region. An electric current is said to exist when there is a net flow of electric charge through a region. In electric circuits this charge is often carried by electrons moving through a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionized gas (plasma).