Aparticle of rest mass m, travelling at speed v in the x-direction, decays into two photons, moving in the positive and negative x-direction relative to the original par ticle. what are their energies? what are the photon energies and directions if the photons are emitted in the positive and negative y-direction relative to the original particle (i. e., perpendicular to the direction of motion, in the particle's rest frame)

Asap 1. which surface feature of the moon is characterized by mountainous areas? question options: maria terrae regolith craters 2.which statement describes surface features called maria on the moon? question options: layers of dust and rock deep areas of cooled lava deep, rocky and barren valleys highlands and mountainous areas

Can anybody me with this? ? (picture included.)

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?