Approximately how much time does light from the Sun take to travel through space and reach the Earth?

Introduction / Context:
This question relates to basic astronomy and the finite speed of light. Although sunlight appears to reach us instantly, it actually takes a measurable amount of time to travel the average distance from the Sun to the Earth. Knowing the approximate travel time helps students appreciate both the enormous speed of light and the large scale of the solar system. This fact often appears in general knowledge and science quizzes.

Given Data / Assumptions:

• The speed of light in vacuum is approximately 3 * 10^8 metres per second.
• The average distance between the Sun and the Earth is about 1.5 * 10^11 metres, often called one astronomical unit.
• We are asked for an approximate time, so a rounded value is acceptable.
• The options include 5 minutes, 4.5 hours, 8 minutes and 5.5 hours.

Concept / Approach:
The time taken by light to travel a given distance is given by time = distance / speed. Using the approximate values, time = (1.5 * 10^11 metres) / (3 * 10^8 metres per second). This calculation gives around 500 seconds, which is a little over 8 minutes. Therefore, the standard rounded statement in textbooks is that sunlight takes about 8 minutes to reach the Earth. The options involving hours are clearly far too large compared to this value.

Step-by-Step Solution:
Step 1: Write the formula for travel time: time = distance / speed. Step 2: Substitute approximate distance from Sun to Earth: distance is 1.5 * 10^11 metres. Step 3: Substitute speed of light in vacuum: speed is 3 * 10^8 metres per second. Step 4: Compute the ratio: time = (1.5 * 10^11) / (3 * 10^8) = (1.5 / 3) * 10^(11 - 8) = 0.5 * 10^3 seconds. Step 5: 0.5 * 10^3 seconds is 500 seconds. Divide by 60 to convert seconds to minutes: 500 / 60 is approximately 8.3 minutes. Step 6: Round to a simple value suitable for general knowledge: about 8 minutes.

Verification / Alternative check:
A quick mental check is to remember that light can circle the Earth multiple times in one second, so taking several hours to reach us from the Sun would be inconsistent with known scales of the solar system. Many introductory astronomy and physics books directly state that it takes about 8 minutes for sunlight to arrive at Earth, and this is a widely accepted educational fact. This confirms that the correct approximate time is about 8 minutes rather than any of the options involving hours or 5 minutes.

Why Other Options Are Wrong:
About 5 minutes is too short, since a simple calculation shows the travel time is closer to 8 minutes. About 4.5 hours is far too long and would imply an unrealistically huge distance or a much lower speed of light, contradicting well established physics. About 5.5 hours is also far too long and inconsistent with basic astronomical data.

Common Pitfalls:
Some learners may confuse the average distance from the Sun to the Earth with larger astronomical distances and overestimate travel time. Others may not be comfortable with powers of ten and therefore fail to perform a quick approximate calculation. To avoid mistakes, it is helpful to memorise the simple fact that light from the Sun takes about 8 minutes to reach Earth and to understand this as a direct consequence of the large distance and finite speed of light.

Final Answer:
Light from the Sun takes about 8 minutes to reach the Earth.