Concepts Of Physics MCQ Edition [Volume 2]
- Exam
- Concepts Of Physics MCQ Edition [Volume 2]
- Subject
- Physics
- Chapter
- The Special Theory of Relativity
Concepts Of Physics MCQ Edition [Volume 2] · Physics · The Special Theory of Relativity
The rest distance between Lucknow and Bhopal is 1000 km . A nonstop...
The rest distance between Lucknow and Bhopal is . A nonstop train travels at . Determine the distance between Lucknow and Bhopal in the train frame.
Options
- A less than
- B less than
- C less than
- D less than
Correct answer
D. less than
Step-by-step solution
The rest distance is .
The speed of the train is .
According to the length contraction formula, the distance in the train's frame is .
Since , using the binomial expansion gives L \approx L_0 \left(1 -\dfrac{v^2}{2c^2}\right).
The decrease in length is \dfrac{L_0 v^2}{2c^2}.
Substituting the values:
\dfrac{10^6 \times (100)^2}{2 \times (3 \times 10^8)^2}
\dfrac{10^{10}}{18 \times 10^{16}}
\dfrac{1}{18} \times
Thus, the distance in the train's frame is less than .
The speed of the train is .
According to the length contraction formula, the distance in the train's frame is .
Since , using the binomial expansion gives L \approx L_0 \left(1 -\dfrac{v^2}{2c^2}\right).
The decrease in length is \dfrac{L_0 v^2}{2c^2}.
Substituting the values:
\dfrac{10^6 \times (100)^2}{2 \times (3 \times 10^8)^2}
\dfrac{10^{10}}{18 \times 10^{16}}
\dfrac{1}{18} \times
Thus, the distance in the train's frame is less than .