An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (2)
Calculate the cost per second: 30 5000 .
Calculate the cost of a 15-second spot: 30 5000 × 15 .
Calculate the total cost for 4 fifteen-second spots: 4 × ( 30 5000 × 15 ) .
The total cost for 4 fifteen-second spots is $10 , 000 .
Explanation
Understanding the Problem We are given that the cost of a 30-second spot on local television is $5,000. We need to find the cost of 4 fifteen-second spots.
Calculating Cost Per Second First, let's find the cost per second for a local television spot. To do this, we divide the cost of a 30-second spot by 30: 30 5000
Calculating Cost of a 15-Second Spot Now, we can calculate the cost of a 15-second spot by multiplying the cost per second by 15: 30 5000 × 15
Calculating Total Cost Finally, we multiply the cost of a 15-second spot by 4 to find the total cost for 4 such spots: 4 × ( 30 5000 × 15 ) = 4 × ( 30 5000 × 15 ) = 4 × ( 30 75000 ) = 4 × 2500 = 10000
Final Answer Therefore, the cost for 4 fifteen-second spots on local television is $10 , 000 .
Examples
Imagine you are a small business owner looking to advertise your products on local television. Understanding the cost structure of TV advertising, such as the cost per second, helps you plan your advertising budget effectively. By calculating the cost for different durations of ad spots, you can optimize your spending and reach your target audience without exceeding your budget. This problem demonstrates how to calculate the cost of advertising spots of different durations based on a given rate.
In total, approximately 2.81 × 1 0 21 electrons flow through an electric device delivering a current of 15.0 A for 30 seconds. This is calculated using the relationship between current, charge, and time. Employing the charge of a single electron, we can determine the total number of electrons.
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