Answer:
Explanation:
This problem is approached using Coulomb's law of electrostatic attraction which states that the force F of attraction or repulsion between two point charges, 
and 
is directly proportional to the product of the charges and inversely proportional to the square of their distance of separation R.
where k is the electrostatic constant.
We can make k the subject of formula as follows;
Since k is a constant, equation (2) implies that the ratio of the product of the of the force and the distance between two charges to the product of charges is a constant. Hence if we alter the charges or their distance of separation and take the same ratio as stated in equation(2) we will get the same result, which is k.
According to the problem, one of the two identical charges was altered from 
to 
and their distance of separation from 
to 
, this also made the force between them to change from 
to 
. Therefore as stated by equation (2), we can write the following;
Therefore;
From equation (4) we now make the new force the subject of formula as follows;
then cancels out from both side of the equation, hence we obtain the following;
From equation (4) we can now write the following;
This could also be expressed as follows;
Answer:
<h2>
<em>6,142mm²</em></h2>
Explanation:
Given the dimension of a paper measured by a ruler as 7.4 cm wide and 8.3 cm long, the area of the paper is expressed using the area for calculating the area of a rectangle as shown;
Area of the piece of paper = Length * Width
Given length = 7.4cm
Length = 74mm (Since 10mm = 1cm)
Width = 8.3cm
Width (in mm) = 83mm
We converted to mm since the ruler used to measure has a division of 1mm.
Substituting the given values into the formula, we will have:
Area of the piece of paper = 74mm * 83mm
Area of the piece of paper = 6,142mm²
<em>Hence, the area of the piece of paper is 6,142mm²</em>
Electromagnetic waves can travel in vaccum but mechanical wave does not
