Since 1983 the standard meter has been defined in terms of which ...

[vinney12]

Since 1983 the standard meter has been defined in terms of which of the following?
 a. specific alloy bar housed at Sevres, France
  b. wavelength of light emitted by krypton-86
  c. distance from the Earth's equator to the North Pole
  d. the distance light travels in a certain fraction of a second
  e. None of the above

Question 2

A ball of relatively low density is thrown upwards. Because of air resistance the acceleration while traveling upwards is 10.8 m/s2 . On its trip downward the resistance is in the opposite direction, and the resulting acceleration is 8.8 m/s2 . When the ball reaches the level from which it was thrown, how does its speed compare to that with which it was thrown?
 a. It is greater than the original speed upward.
  b. It is the same as the original speed upward.
  c. It is less than the original speed upward.
  d. Without knowing the original speed, this problem cannot be solved.

[jjorrostieta]

Answer to Question 1

d

Answer to Question 2

c

[vinney12]

Excellent

[JaynaD87]

Gracias!