Answer:
The answer is A because the equation is KEi+PEi=KEf+PEf
i means initial (before) and f means final (after)
<h2>QUESTION:- It is easier to lift the same load by using three pulley system than by using two-pulley system.</h2>
<h2>ANSWER:- IN CASE OF IDEAL PULLEY SYSTEM</h2>
<h2>REASON:- </h2>
Logic behind is lies behind the mechanical advantage of the provided bt the Pulley system.
as if we calculate the mechanical advantage of the 2 Pulley system we will have the value 2
And if we will calculate the mechanical advantage of the 3 pulley system then we will get the value of 3
so due to extra mechanical advantage we feel it easy to move with 3 pulley system then 2 Pulley system

Answer:

Explanation:
-The chemical formula for Molybdenum (V) Dichromate is 
-There are 21 moles of oxygen per one mole of Molybdenum (V) Dichromate
-We apply Avogadro's constant to find the number of atoms of oxygen:

Hence, there are