Author Question: A spacecraft is measured by an observer on the ground to have a length of 53 m as it flies toward ... (Read 42 times)

vinney12 · **on:** Jul 29, 2018

A spacecraft is measured by an observer on the ground to have a length of 53 m as it flies toward the earth with a speed 1.7 108 m/s.

The spacecraft then lands and its length is again measured by the observer on the ground, this time while the spacecraft is at rest on the launchpad. What result does he now get for the length? (c = 3.00 108 m/s)

Question 2

An astronaut leaves Earth in a spaceship at a speed of 0.960c relative to an observer on Earth. The astronaut's destination is a star system 14.4 light-years away (one light-year is the distance light travels in one year.

) According to the astronaut, how long does the trip take? A) 14.4 y
B) 22.7 y
C) 9.34 y
D) 15.0 y
E) 4.20 y