Calculate the length of a 120m (as measured by the astronaut) spaceship travelling at 0.85c as measured by a stationary observer

The length of the spaceship of 120m was measured at rest relative to the spaceship so we will take that as the proper length, dennoted Lproper
We first calculate the Lorentz factor:
Ɣ = 1/sqrt(1-(v/c)2)
Ɣ = 1/sqrt(1-0.852)
Ɣ = 1.8986... (Keep this number in your calculator as rounding now will affect your final answer)
Now, relate this to the formula for length contraction:
L = Lproper / Ɣ
L = 120/1.8986...
L = 63.2m as measured by the stationary observer

Answered by Kerr M. Physics tutor

3398 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

What is a stationary wave?


An ideal gas within a closed system undergoes an isothermal expansion from an initial volume of 1m^3 to 2m^3. Given that the initial pressure of the gas is 10^5 Pa, find the final pressure of the gas following the expansion.


From the 2016 OCR B paper A ball is thrown at an angle of 30 Degrees to the horizontal. The initial kinetic energy of the ball is K. Air resistance is negligible. What is the kinetic energy of the ball at the maximum height.


Calculate the temperature rise of a mass due to energy transfer over time.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences