An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (2)
Start with the given formula: K = L MN .
Divide both sides by L N to isolate M : L N K = L N L MN .
Simplify the equation: M = L N K .
The formula for M is M = K / L N .
Explanation
Understanding the Problem We are given the formula K = L MN and asked to find the formula for M . This involves isolating M on one side of the equation.
Isolating M To isolate M , we need to divide both sides of the equation by L N . This gives us:
Solving for M L N K = L N L MN L N K = M
Final Answer Therefore, the formula for M is M = L N K .
Examples
In physics, if you know the total energy (K) of an object and have formulas for its length (L) and mass (N) that relate to its energy, you can find a specific property M using the formula we derived. For example, if K represents kinetic energy, L represents a length-related parameter, and N represents mass, M could represent a velocity component. Rearranging formulas like this is crucial in many scientific and engineering calculations to solve for unknown variables based on known quantities.
A device delivering a current of 15.0 A for 30 seconds allows approximately 2.81 × 1 0 21 electrons to flow through it. This is calculated using the relationship between current, charge, and the charge of a single electron. The total charge is found to be 450 C , and dividing that by the charge of an electron gives the number of electrons.
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