Answer:
Option A. 11
Explanation:
The atomic number of an element does not change.
Recall:
Atomic number = proton number
If the atom is neutral, then,
Proton number = electron number
Since the element is sodium, then, the atomic number of sodium–25 is 11.
Also, we were told to obtain the electrons of a neutral atom of sodium–25
Therefore,
Atomic number = proton number = 11
Since the atom is neutral,
Proton number = electron number = 11
Answer:
Let the weight of the ruler be X.
Now X acts in the middle, so we have 55-50 = 50cm
Since left hand movement= right hand movement
X(55-50)=90(95-55)
5X= 90×40
X=320cm
Hence the weight of the ruler is 320g
Explanation:
The minimum force required to lift the box at constant velocity is determined as 274.4 N.
<h3>
Minimum force required</h3>
The minimum force required to lift the box at constant velocity is the tension in one of the pulleys, and the magnitude is calculated as follows;
2T = mg
where;
- m is mass of the box
- T is the minimum force required
2T = mg
T = mg/2
T = (56 x 9.8)/2
T = 274.4 N
Learn more about minimum force here: https://brainly.in/question/47873510
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Answer:
The answer of this question is :- Virtual image
