Question

A clock battery wears out after moving 10,000 C of charge through the clock at a rate of 0.500 mA.

(a) How long did the clock run?

a) 20,000 hours
b) 50,000 hours
c) 2.00 hours
d) 25,000 hours

Answer 1

The clock ran for approximately 5,556 hours and 20,000,000 electrons flowed per second.

Step-by-step explanation:

The clock battery moves 10,000 C of charge through the clock at a rate of 0.500 mA. To find the time the clock ran, we can use the equation:

Charge (C) = Current (A) x Time (s)

Rearranging the equation, we have:

Time (s) = Charge (C) / Current (A)

Plugging in the values, we get:

Time (s) = 10,000 C / 0.500 mA

Converting mA to A, we divide 0.500 mA by 1000 to get 0.0005 A:

Time (s) = 10,000 C / 0.0005 A = 20,000,000 seconds

Converting seconds to hours, we divide 20,000,000 seconds by 3600:

Time (h) = 20,000,000 s / 3600 = 5,555.56 hours

Rounded to the nearest hour, the clock ran for approximately 5,556 hours.

To find the number of electrons per second that flowed, we will use the equation:

Current (A) = Charge (C) / Time (s)

Plugging in the values:

0.500 mA = 10,000 C / Time (s)

Converting mA to A, we divide 0.500 mA by 1000 to get 0.0005 A:

0.0005 A = 10,000 C / Time (s)

Rearranging the equation, we have:

Time (s) = 10,000 C / 0.0005 A = 20,000,000 seconds

Therefore, 20,000,000 electrons flowed per second.