A Spaceship Is Moving Away from an Observer at Relativistic

Multiple Choice

A spaceship is moving away from an observer at relativistic speed.Its length at rest is 100 m,but the observer measures its length as 60 m.A time interval of 84 s on the spaceship would be measured by the observer to be which of the following?

A) 50.4 s
B) 30.2 s
C) 134 s
D) 140 s
E) ​84 s