El arco iris es un fenómeno que se produce principalmente por: I. refracción de la luz
II. reflexión total interna de la luz
III. Interferencia luminosa
a) sólo I
b) sólo II
c) sólo III
d) sólo I y II

Ahorizontal wire is tied to supports at each end and vibrates in its second-overtone standing wave. the tension in the wire is 5.00 n, and the node-to-node distance in the standing wave is 6.28 cm. (a) what is the length of the wire? (b) a point at an anti- node of the standing wave on the wire travels from its maximum upward displacement to its maximum downward displacement in 8.40 ms. what is the wire's mass?

The consumption of fossil fuels could be

The long handle on a rake is a(n) a. lever b. screw c. wedge d. inclined plane