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 initial balance: $944.88 .
Add all deposits: + $390.36 + $390.36 = + $780.72 .
Subtract all checks and debits: − $455.00 − $9.20 − $251.59 = − $715.79 .
Calculate the ending balance: $944.88 + $780.72 − $715.79 = $1 , 009.81 .
Explanation
Understanding the Problem We need to calculate Richard's ending balance by considering his initial balance and all the transactions (checks, deposits, and debits) that occurred during the period. We will add the deposits and subtract the checks and debits from the initial balance to find the final balance.
Listing Transactions The initial balance is $944.88. The transactions are as follows:
Check #204: -$455.00
Payroll deposit: +$390.36
Debit: -$9.20
Check #205: -$251.59
Payroll deposit: +$390.36
Calculating the Ending Balance Now, let's calculate the ending balance by adding and subtracting the transactions from the initial balance:
Ending Balance = Initial Balance + Deposits − Checks and Debits
Ending Balance = 944.88 − 455.00 + 390.36 − 9.20 − 251.59 + 390.36
Ending Balance = 944.88 + 390.36 + 390.36 − 455.00 − 9.20 − 251.59
Ending Balance = 1725.60 − 715.79
Ending Balance = 1009.81
Final Answer Therefore, Richard's ending balance is $1 , 009.81 .
Examples
Checkbook balancing is a fundamental skill in personal finance. For example, if Richard is managing his monthly expenses, accurately tracking his checkbook helps him avoid overdraft fees and ensures he knows exactly how much money he has available. This is similar to how businesses manage their accounts payable and receivable to maintain a healthy cash flow. By keeping a precise record, Richard can also plan his budget more effectively, allocating funds for rent, car payments, and other expenses.
The total charge that flows through the device is 450 C. This corresponds to approximately 2.81 x 10^21 electrons flowing through it over 30 seconds. To calculate this, we used the formula relating current, time, and charge, and converted the charge to the number of electrons using the charge of a single electron.
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