Astring is stretched between a fixed support and a pulley a distance 111 cm apart. the tension on the string is controlled by a weight hanging from the string below the pulley. an electomechnical vibrator is used to vibrate the string at 120 hz. when the weight is adjusted to 275 g, the string is found to oscillate in its third standing wave mode (three loops). what is the speed of wave propogation on the string in this mode?

88.8 m/s= Speed of wave propagation in the required mode.(3 loops)

Explanation:

When there are 3 loops.  

the total length = L = 3 λ /2

⇒ λ  = 2 L / 3 = 2 ( 1.11 ) / 3 = 0.74 m

Velocity = v = f λ = (120)(0.74) = 88.8 m/s

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.