Final answer:
Barnes should record a Credit to Accounts Receivable and a Debit to Cash for $2,000 upon receipt of the payment.
Step-by-step explanation:
The journal entry Barnes should record upon the receipt of the $2,000 payment from the customer would be:
Credit to Accounts Receivable for $2,000
Debit to Cash for $2,000
This entry reflects the reduction in the Accounts Receivable balance, as the customer has made a payment on the outstanding amount. The Cash account is debited to show the increase in cash received from the customer.