🔍 Key Concepts

• Relationship between degrees of arc and time of the Earth’s rotation (15° of longitude = 1 hour of time) • How to convert minutes and seconds of arc into decimal degrees • How to convert hours of time into minutes and seconds of time

💭 Think About

• First, convert 5? 54' into a pure angular value (think: degrees and minutes). What is the total angle in degrees? • Use the fact that the Earth turns 360° in 24 hours. How much time corresponds to 1° of longitude? • Once you know the time for 1°, multiply by your total number of degrees and then break the result back into minutes and seconds of time.

✅ Before You Answer

• Be sure you are using 15° = 1 hour = 60 minutes of time, not 1° = 60 minutes of time (that’s arc, not time). • Carefully distinguish between minutes of arc and minutes of time; they are different units. • After calculating, confirm your final answer’s minutes and seconds of time match one of the choices exactly, with no rounding mistakes.