The force of friction is given by:
f = μR, where μ is the friction coefficient and R is the reaction force, which will be equal to the weight.
100 = μ x 130
μ = 0.77
Taking into account the rule of three for the change of units, the mass of the book is 45600 miligrams.
First of all, the rule of three is a mathematical tool that helps you quickly solve proportionality problems.
Having three known values and one unknown, a proportional relationship is established between all of them in order to find the fourth term of the proportion.
If the relationship between the magnitudes is direct (when one magnitude increases, so does the other; or when one magnitude decreases, so does the other), the rule of three is applied as follows, where a, b and c are known values and x is the unknown to calculate:
a → b
c → x
So: 
Being 1 kg equivalent to 1000000 milligrams, In this case the rule of three is applied as follows: if 1 kg equals 1000000 milligrams, 4.56×10⁻² kg equals how many milligrams?
1 kg → 1000000 milligrams
4.56×10⁻² kg → x
So:

<u><em>x=45600 miligrams</em></u>
In summary, the mass of the book is 45600 miligrams.
Learn more:
Hi there!
Informative writing has the intent to inform or educate us on a particular topic or event. It gives us more information and insight onto something.
Persuasive writing has the intent of convincing us to believe in a certain idea or to perform a certain action. For instance, advertisements have a persuasive intent; they are persuading us to buy a product or service.
Argumentative writing is similar to persuasive writing in the sense that they are persuading us to believe a certain idea. However, they are often based on logic and fact rather than opinions.
Let's look at the first excerpt.
<em>This morning at 9 a.m., a school bus collided with a car at the intersection of Osmena and Cabrera streets. The passengers were not injured, but the medical personnel checked each student as well as the driver before they were transported to their school.</em>
This text doesn't try to convince us in believing something. It doesn't argue anything and it only tries to give us more insight onto the event, which is a car accident. No opinions are stated and only events are given.
Therefore, this excerpt uses an informative writing technique.
Answer:
A dependent variable is a variable that is tested in an experiment. An independent variable is that can be modified. Depending on what you are testing, the dependent variable will change accordingly to the dependent variable.
- I'm reading this back and it doesn't make much sense, if you want me to reword this I can