To convert a temperature from Kelvin (K) to degrees Celsius (°C), we use the following relationship:
[tex]\[ \text{Temperature in } °C = \text{Temperature in } K - 273.15 \][/tex]
Given the temperature in Kelvin is \( 49 \, K \), we can find the equivalent temperature in Celsius with these steps:
1. Start with the given temperature in Kelvin, which is \( 49 \, K \).
2. Subtract 273.15 from the Kelvin temperature:
[tex]\[
49 \, K - 273.15
\][/tex]
By performing this subtraction:
[tex]\[
49 - 273.15 = -224.15
\][/tex]
Therefore, the temperature of the substance in degrees Celsius is:
[tex]\[ -224.15^{\circ} C \][/tex]
Since we’re selecting from the closest given options, the closest and correct value is:
[tex]\[ -224^{\circ} C \][/tex]
Hence, the temperature of a substance at [tex]\( 49 \, K \)[/tex] is [tex]\(-224^{\circ} C \)[/tex].