The observed relativistic length of a super rocket moving by the observer at 0.70c will be what factor times that of the measured rocket length if it were at rest?
A)0.55
B)0.71
C)0.51
D)1.4
E)1.8

Question

The observed relativistic length of a super rocket moving by the observer at 0.70c will be what factor times that of the measured rocket length if it were at rest?
A)0.55
B)0.71
C)0.51
D)1.4
E)​1.8

Quizplus · Accepted Answer

The observed relativistic length contraction can be calculated using the formula $L = L_0\sqrt{1 - v^2/c^2}$, where $L_0$ is the rest length, $v$ is the velocity of the object, and $c$ is the speed of light. Plugging in $v = 0.70c$, we get $L = L_0\sqrt{1 - 0.49} = L_0\sqrt{0.51}$, which is approximately $L = 0.71L_0$.

The Observed Relativistic Length of a Super Rocket Moving by the Observer