An electric light is plugged into a 120-V outlet. If the current in the bulb is 0.5 A, how much electrical energy is used by the bulb in 15 minutes?
A toaster is plugged into an outlet where the voltage difference is 120 V. How much power does the toaster oven use if the current in the oven is 10 A?
6. A video-disc player is not playing still uses 6.0 W of power. What is the current into the video-disc player if it is plugged into a standard 120-V outlet?
Well, let's brighten up this question with a humorous answer!
So, an electric light walks into a 120-V outlet... It says, "Wow, this place is electrifying!"
Now, let's calculate the electrical energy used by the bulb in 15 minutes. To do this, we'll use the formula:
Energy (in joules) = Power (in watts) × Time (in seconds).
First, we need to find the power. The power is given by the product of voltage and current, so
Power = Voltage × Current
Power = 120 V × 0.5 A
Power = 60 watts.
Now, let's convert 15 minutes to seconds. There are 60 seconds in a minute, so 15 minutes is equal to 900 seconds.
So, the energy used by the bulb is:
Energy = 60 watts × 900 seconds
Energy = 54,000 joules.
Therefore, the electrical energy used by the bulb in 15 minutes is 54,000 joules. That's one electrifying lightbulb!
To calculate the electrical energy used by the bulb, we can use the formula:
Energy (in joules) = Power (in watts) × Time (in seconds)
First, we need to calculate the power consumed by the bulb.
The power is given by the equation:
Power (in watts) = Voltage (in volts) × Current (in amperes)
In this case, the voltage is 120 V and the current is 0.5 A.
Power = 120 V × 0.5 A = 60 watts
Now, we need to convert the time from minutes to seconds. There are 60 seconds in a minute, so 15 minutes is equal to 15 × 60 = 900 seconds.
Using the formula for energy, we can calculate:
Energy = Power × Time = 60 watts × 900 seconds
Now, we can plug this into a calculator to find the answer:
Energy = 54,000 joules
Therefore, the electric light bulb uses 54,000 joules of electrical energy in 15 minutes.
P = EI = 120 * 0.5 = 60W
1W = 1J/s, so
60W = 60J/s * 900s = 54000J