Physics - Waves

anpanman SG

1 Is a deeper region (in the water) the part where it has the longer wavelength and faster wave speed?

2 1 ohm/sec is the same as

A 1 V

B 1 A

C 1 C

D 1 W

3 A survivor from a shopwreck lands on an island lying 3000 m away from a vertical cliff. He observes a ship anchored between the island and the cliff. A blast from the ship's siren is heard twice with a time lapse of 4 s. Calculate the distance of the ship from the island. Take speed of sound = 330m/s

*Edited: Relooked at the question. Here's what I did.

330 X 4 = 1320 m (dist. sound travels from ship to cliff)

dist. of ship to cliff = 1320/2 = 660m

dist. of ship from island = 3000 - 660 = 2340 m.

Not sure if it's right.

4 When you have a bimetallic strip and it gets heated up, does the more "expandable" metal move inwards/outwards? I think it's outwards

5 Is it correct to say that diffusion is the spreadin gof molecules from a region of higher pressure to a region of lower pressure? There area other answers like (of their own accord w/o external aid, as a result of temperature difference, due to intermolecular forces of attraction) But I think the first answer is the "most correct".

SBS2601D SG

1. Yes. When the water is shallow, friction from the land beneath slows the wave down and forces the displacement of the particles more longitudinally rather than laterally.

ThunderFbolt SG

no idea for 1

for 2, are you sure that you wrote the question correctly?

if you do it the old fashion way that V = IR, I = q/t and q = CV, you would get R/t = V/q = 1/C, which doesn't quite fit into your options.

for 3, you got it.

for 4, my grammar fails me, so no idea =P

for 5, i always kind of remembered diffusion as the movement of particles from a region of higher concentration to a region of lower conc by random movement. i suppose you could say what you said when it applies to a particular gas in a room, but not so for mixed liquids and gases.

eagle SG

1. Yes. When the water is shallow, friction from the land beneath slows the wave down and forces the displacement of the particles more longitudinally rather than laterally.

Interesting... I didn't think of that explanation... :D

Learned something

eagle SG

For Q4

bimetallic strip: The one that expands more will be on the outer side when it bends. This is because the length of the outer side is larger.

For Q5

i always kind of remembered diffusion as the movement of particles from a region of higher concentration to a region of lower conc by random movement. i suppose you could say what you said when it applies to a particular gas in a room, but not so for mixed liquids and gases.

For gases, when there's higher concentration one side, there's higher pressure ;)

ThunderFbolt SG

For Q5

For gases, when there's higher concentration one side, there's higher pressure ;)

*nods* but I think his definition only applies to a particular gas when injected into a vacuum, as it is also possible for 2 gases of the same pressure to diffusion "into each other" when put together (brownian motion). not really accurate to take only the pressure of individual gases in a mix of gases.

eagle SG

yup

that's why I wrote in the guidelines to post the full question, not just part of it

SBS2601D SG

Interesting... I didn't think of that explanation... :D

Learned something

It was more of a general knowledge geog related question...

Related would be the many accounts of seawater receding my kilometres before the tsunami hits land. This is caused by the massive longitudinal displacement of the water caused by resistence from the progressively shallow seabed. This is better known as wave shoaling...