How many calories of heat will be approximately developed in a `210 W` electric bulb in `5 min`?

Options

A. `15,000`
B. `1050`
C. `63,000`
D. `80,000`

Explanation

To find out how many calories of heat will be developed in a 210 W electric bulb in 5 minutes, we can follow these steps:

### Step 1: Understand the power of the bulb
The power of the electric bulb is given as 210 W. This means that the bulb produces 210 joules of energy per second.

### Step 2: Convert the time from minutes to seconds
Since the power is given in joules per second, we need to convert the time from minutes to seconds.
- 5 minutes = 5 × 60 seconds = 300 seconds.

### Step 3: Calculate the total energy produced in joules
Now, we can calculate the total energy produced by the bulb in 5 minutes (300 seconds).
- Total energy (in joules) = Power (in watts) × Time (in seconds)
- Total energy = 210 W × 300 s = 63,000 joules.

### Step 4: Convert joules to calories
To convert joules to calories, we use the conversion factor:
1 calorie = 4.2 joules.
Thus, to convert joules to calories, we can use the formula:
- Total energy (in calories) = Total energy (in joules) / 4.2
- Total energy (in calories) = 63,000 J / 4.2 ≈ 15,000 calories.

### Final Answer
The total heat developed in a 210 W electric bulb in 5 minutes is approximately **15,000 calories**.

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