Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A LASER is a source of very intense, monochromatic and unidirectional beam of light. These properties of a laser light can be exploited to measure long distances. The distance of the Moon from the Earth has been already determined very precisely using a laser as a source of light. A laser light beamed at the Moon takes 2.56s to return after reflection at the Moon's surface. How much is the radius of the lunar orbit around the earth?
PhysicsUnits and Dimensions
Solution:
2569 Upvotes Verified Answer
Here $t=256 \mathrm{~s}, c=3 \times 10^8 \mathrm{~ms}^{-1}$
Radius of the lunar orbit around the earth $=$ Distance of the moon from the earth $=\frac{c \times t}{2}=\frac{3 \times 10^8 \times 2.56}{2}=3.84 \times 10^8 \mathrm{~m}$.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.