Heat produced by 100 W heater in 2 minutes is:

Options

A. `10.5` kcal
B. `16.3` kcal
C. `2.8` kcal
D. `14.2` kcal

Explanation

To find the heat produced by a 100 W heater in 2 minutes, we can use the formula:

\[ Q = P \times t \]

where:
- \( Q \) is the heat produced (in joules),
- \( P \) is the power of the heater (in watts),
- \( t \) is the time for which the heater is on (in seconds).

### Step 1: Convert time from minutes to seconds
Given time is 2 minutes. We need to convert this into seconds:

\[ t = 2 \text{ minutes} \times 60 \text{ seconds/minute} = 120 \text{ seconds} \]

### Step 2: Use the formula to calculate heat
Now we can substitute the values into the formula:

- Power, \( P = 100 \text{ W} \)
- Time, \( t = 120 \text{ seconds} \)

Now, calculate \( Q \):

\[ Q = P \times t = 100 \text{ W} \times 120 \text{ seconds} \]

### Step 3: Perform the multiplication
Calculating the above expression:

\[ Q = 100 \times 120 = 12000 \text{ J} \]

### Step 4: Convert joules to kilojoules
To express the heat in kilojoules, we convert joules to kilojoules:

\[ Q = \frac{12000 \text{ J}}{1000} = 12 \text{ kJ} \]

### Final Answer
The heat produced by the 100 W heater in 2 minutes is:

\[ Q = 12 \text{ kJ} \]

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