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 new unit of length is chosen such that the speed of light in vacuum is unity. What is the distance between the Sun and the Earth in terms of the new unit, if light takes $8 \mathrm{~min}$ and $20 \mathrm{sec}$ to cover this distance?
PhysicsUnits and Dimensions
Solution:
2365 Upvotes Verified Answer
Velocity of light $\mathrm{c}=1$ new unit of length $\mathrm{s}^{-1}$
Time taken by light of Sun to reach the Earth $=t=8 \min 20 \mathrm{~s}=8 \times 60+20=500 \mathrm{~s}$
$\therefore \quad$ Distance between the Sun and Earth,
$x=c \times t=1$ new unit of length $\mathrm{s}^{-1} \times 500 \mathrm{~s}$
$=500$ new units of length.

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.