A particle is moving with a certain speed. Its speed and energy ...

[jlmhmf]

A particle is moving with a certain speed. Its speed and energy are being measured with respect to Earth. When the particle's speed doubles, the energy increases by a factor of 4. What was the original speed of the particle?
 
  A) 0.447c
  B) 0.488c
  C) 0.523c
  D) 0.648c
  E) 0.800c

Question 2

Two objects, A and B, are rubbed together. As a result, object A acquires an excess negative charge while object B becomes positively charged. In comparison to their masses before the charging process, you can say that
 
  A) the mass of both objects increased.
  B) the mass of A increased and that of B decreased.
  C) the mass of A decreased and that of B increased.
  D) the mass of both objects decreased.
  E) None of the other choices is correct.

[fur]

Answer to Question 1

B

Answer to Question 2

B

[jlmhmf]

Excellent

[bulacsom]

TYSM