You are in a spaceship moving past Earth at nearly lightspeed and ...

[DelorasTo]

You are in a spaceship moving past Earth at nearly lightspeed and you observe Mort, who is on Earth. You measure his mass, pulse rate, and size. How are they different from the values measured by Mort himself?
 
  A) Mass has decreased, pulse rate has speeded up, and size is reduced along the direction of motion.
  B) Mass has increased, pulse rate has speeded up, and size is reduced along the direction of motion.
  C) Mass has increased, pulse rate has slowed down, and size is reduced along the direction of motion.
  D) They are unchanged, i.e., they are normal.
  E) Mass has decreased, pulse rate has slowed down, and size is reduced along the direction of motion.

Question 2

A ball vibrates back and forth from the free end of an ideal spring having a force constant (spring constant) of 20 N/m.
 
  If the amplitude of this motion is 0.30 m, what is the kinetic energy of the ball when it is 0.30 m from its equilibrium position?
  A) 0.45 J B) 0.90 J C) 0.22 J D) 0.00 J E) 1.4 J

[coreycathey]

Answer to Question 1

C

Answer to Question 2

D

[DelorasTo]

Thanks for the timely response, appreciate it

[lkanara2]

Gracias!