Two fixed navigation beacons mark the approach lane to a star. the beacons are in line with the star and are 87 mm apart. a spaceship approaches the star with a relative velocity of 0.7 c and passes the beacons. as the ship passes the first beacon the ship emits a short radar pulse toward the second beacon, and the radar echo is received at the ship. the time interval between the emission of the radar pulse and the reception of the radar echo is closest to:
answer choices: 480 ms, 150 ms, 370 ms, and 340 ms

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

The a992 steel rod bc has a diameter of 50 mm and is used as a strut to support the beam. determine the maximum intensity w of the uniform distributed load that can be applied to the beam without risk of causing the strut to buckle. take f.s. = 2 against bucklin

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?