Answer:
<h3><em><u>Magnesium has an atomic number of 12, which means its neutral atom has 12 electrons. The Mg2+ ion is formed when the neutral magnesium atom loses 2 electrons, which brings its total number of electrons to 10</u></em></h3>
<h2>
Answer:</h2>
d. An object did work on the environment.
<h2>
Explanation:</h2>
Work is defined in many contexts. Some of these are;
i. <em>Work is the product of force and displacement</em>. In this case, work done is positive if the force applied on an object or body and the displacement caused by the force are in the same direction. If instead the force and displacement are in opposite direction, then the work done will be negative. If it is the case the force and the displacement are perpendicular to each other, the work done is zero.
ii. In the first law of thermodynamics, the internal energy of a system is the sum of the work done and the heat exchanged between the system and the environment. Therefore, <em>work done is the difference between the internal energy of a system and the heat exchanged between the system and the environment</em>.
In this case, work is said to be positive if work is done by the system (object) on the environment. It is negative if work is done by the environment on the system (object).
Answer:
Mass of 17.854 kg is only attached to the spring
Explanation:
We have given time period in first case is 22 sec
Let initially mass is m
After 22 kg are added the period becomes 33 sec
Time period of spring mass system is
, here m is mass and k is spring constant
From the relation we can see that
Squaring both side
m = 17.584 kg
So mass of 17.854 kg is only attached to the spring
To solve this problem we will apply the concepts related to the kinematic equations of linear motion. For such an effect we will define the average speed, as the distance traveled in the established time.
Our values are given under the following conditions:
The final distance covered in those 10 seconds at 
would be
Therefore the average speed would be the sum of those distances in the total travel time
Therefore the average velocity is 30.5m/s
Answer:
Weightlessness
Explanation:
When the elevator is in free fall, this can only occur when the cord of the elevator breaks.
The acceleration of the elevator will be equal to the acceleration due to gravity. That is:
a = g
Then, the body will experience what we called WEIGHTLESSNESS
Where the normal reaction N of the person will tend to zero. That is
N = 0
The value of FN < 0 because the person inside the lift will experience weightlessness.
