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:
1. <span>the low pressure is moving slower than expected.
This make the meteorologist receive premature data which make them fail to interpret the data correctly and make the wronf prediction.
2. Sudden change in wind direction, which transfer the natural occurence into other region than where it initially predicted
3. We still haven't developed the methodology to 100% predict natural occurence</span>
<span>Chronological essays by the definition of a chronological
meaning in order. There is an order in a specific writing. Like a history write
up from a certain happening years ago. It
is different from procedural essays because these are essays who are giving
instructions of certain set up to guide the person accordingly in doing
something to make it more accurate. Like recipes, instructions in playing, etc.
Example words that are used in chronological essays are first, second, third,
fourth, fifth, next, after, then, lastly, finally, consequently, in addition,
thus, therefore, however, etc.</span>
Answer: 90 kgm/s
Explanation:
The momentum (linear momentum) 
is given by the following equation:
Where:
is the mass of the skater
is the velocity
In this situation the skater has two values of momentum:
Initial momentum: 
Final momentum: 
Where:
So, if we want to calculate the difference in the magnitude of the skater's momentum, we have to write the following equation(assuming the mass of the skater remains constant):
Finally:
Answer:
2) zero acceleration
Explanation:
Motion can be defined as a change in the location (position) of a physical object or body with respect to a reference point.
This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.
Mathematically, the motion of an object is described in terms of time, distance, speed, velocity, position, displacement, acceleration, etc.
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
Generally, an object is said to be in equilibrium when neither the energy possessed by the object not state of motion changes with respect to time. Thus, the vector sum of all the forces acting upon an object that's in equilibrium is zero.
In conclusion, an essential characteristic of an object in equilibrium is zero (0) acceleration because there's no change in its velocity with respect to time.
