That is called the<u> variable</u> because it varies/changes in the experiment,
it's like x in algebra (with more than one placeholder), if it changes, it normally gives you a different result
The empirical formula of this compound is 
<h3>Empirical formula </h3>
To calculate the empirical formula of a compound, the value of moles of each element is needed.
As we have the information of the mass value, we will use the molar mass expression, which corresponds to:





As the value of the empirical formula must be an integer, simply multiply the two values by a common factor:


So, the empirical formula of this compound is
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Learn more about empirical formula: brainly.com/question/1247523
Answer: Friction is a force that resists relative motion between two surfaces in contact. Depending on the application, friction may be desirable or undesirable.
Use the Heat formula for both problems.
q=m*c*∆t
Where
q= heat in Joules
m= mass in grams
c= specific heat which is a constant 4.18
∆t= change in temperature