To determine how many hours it will take for the temperature to increase from -5 degrees to 16 degrees, let's follow these steps:
1. Find the total temperature increase needed:
- The current temperature is -5 degrees.
- The target temperature is 16 degrees.
- The difference between the target temperature and the current temperature can be calculated as:
[tex]\[
\text{Total increase needed} = 16 \, \text{degrees} - (-5 \, \text{degrees})
\][/tex]
- Subtracting a negative is the same as adding, so:
[tex]\[
\text{Total increase needed} = 16 + 5 = 21 \, \text{degrees}
\][/tex]
2. Determine the rate of temperature increase:
- The temperature increases at a rate of 3 degrees per hour.
3. Calculate the total number of hours required:
- To find out how many hours it will take to reach the target temperature, divide the total temperature increase needed by the rate of increase:
[tex]\[
\text{Hours needed} = \frac{\text{Total increase needed}}{\text{Rate of increase per hour}}
\][/tex]
- Plugging in the numbers:
[tex]\[
\text{Hours needed} = \frac{21 \, \text{degrees}}{3 \, \text{degrees per hour}} = 7 \, \text{hours}
\][/tex]
Therefore, it will take 7 hours for the temperature to increase from -5 degrees to 16 degrees.
