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good question

Animals can rain from the sky

Raining animals is a relatively common meteorological phenomenon, with occurrences reported from many countries throughout history. The animals most likely to drop from the sky in a rainfall are fish and frogs, with birds coming third. Sometimes the animals survive the fall, especially fish, suggesting a small time gap between the extraction and the actual drop. Several witnesses of raining frogs describe the animals as startled, though healthy, and exhibiting relatively normal behavior shortly after the event. In some incidents, however, the animals are frozen to death or even completely enclosed in blocks of ice. These occurrences may be evidence for the transport of the victims to high altitudes, where the temperature is below zero, and they show how powerful meteorological forces can be. Most recent occurrences include the rain of frogs and toads in Serbia (2005) and London (1998), and rains of fish in India (2006) and Wales (2004).

In Honduras, the Lluvia de Peces (Rain of Fishes) is a unique phenomenon that has been occurring for more than a century on a yearly basis in the country of Honduras. It occurs in the Departamento de Yoro, between the months of May and July. Witnesses of this phenomenon state that it begins with is a dark cloud in the sky followed by lightning, thunder, strong winds and heavy rain for 2 to 3 hours. Once the rain has stopped, hundreds of living fish are found on the ground. People take the fish home to cook and eat them. Although some experts have tried to explain the Rain of Fishes as a natural meteorological phenomenon, the fish are not sea water fish, but fresh water fish; they are not dead, but alive; they are not blind, they have eyes; they are not big fish, but small; and the type of fish is not found elsewhere in the area. There is no valid scientific explanation for this phenomenon. Many people believe this phenomenon occurs because of Father José Manuel Subirana, a Spanish catholic missionary and considered by many to be a Saint. He visited Honduras from 1856-1864, and upon encountering so many poor people, prayed for 3 days and 3 nights asking God for a miracle to help the poor people by providing food. The Rain of Fishes has occurred ever since.

Source:internet

hsbhatt's soln is incorrect

in the above soln
?=alpha

F-T-f=Ma ----1
T-f=ma ----2
fR=I?
?=2f/mR [I=mRR/2)
also for rolling R?-a=a
therefore ?=2a/R=2f/mR
therefore f=ma

1+2----
F-2f=(M+m)a
F-2ma=Ma+ma
F=(M+3m)a
therefore a=F/M+3m

Cheers!!

Well what I can think is this--

the boat with scrap iron would displace more water than boat alone+scrap alone. this is because boat + scrap iron would displace water equal to volume of boat submerged without stone(v1) +due to weight of stone(v2). however when scrap iron would be thrown. boat will displace water equal to v1 and scrap iron would sink hence it will displace v3=less water than what its weight would ie v3<v2, therefore v1+v2>v1+v3, thus the water level would fall.

well taking any wave-y=asin(wt-kx)
its phase is wt-kx
if we take another wave y=asin(wt-kx+phi)
its phase is wt-kx+phi
therefore phase diff=wt-kx+phi-(wt-kx)=phi
Hoping that its helpful!

are you now clear about the derivation?

have a look at
http://www.goiit.com/posts/list/games-puzzles-and-quizzes-cool-facts-gain-some-knowledge-41865.htm

well i have not taken them in phase. there is phase difference- wt-kx-(wt+kx)=-2kx.
talking of phase difference of pie it doesnot need be taken here as we are considering two different waves of same frequency travelling in opposite direction and not one wave which forms a standing wave after reflection from a rigid support.

y1=Asin(wt-kx)
y2=Asin(wt+kx) [travelling in opp. direction]
using principle of superposition--
y=y1+y2
=A[sin(wt-kx)+sin(wt+kx)]
=2Asin(wt)cos(kx)

well the nature of image does not vary.
the only thing that has to be done is to consider the cut part as a normat convex lens and then solve.

a bit more for you-7.5

The Speed of Light

Most people usually think of the speed of light as being really fast. It's 671 million miles per hour. That seems tantalizingly zippy if you're caught in traffic.

However, once you think about the speed of light within the context of our solar system, it starts to seem unimpressive.

It takes about 1.3 seconds for light or radio waves to reach us from the Moon, which really isn't all that far away (it's only 20 times farther away than Australia is to the United States). This was an issue during the Apollo space program, because due to the round trip time of the radio signals, NASA had to wait about three seconds to hear the answer to every question they asked the astronauts.

When Mars is closest to the Earth, it takes light three minutes to travel between the two planets. If you asked a question to an astronaut on Mars, you'd have to wait at least six minutes for an answer, and Mars is usually a lot farther away than that. At its greatest distance, you'd have to wait 42 minutes, or even longer if the astronaut is watching Gilmore Girls. In the future, there will be no such thing as sending an "instant message" to your friends on the Mars base. There also won't be any day trading or free pizza delivery.

The Voyager 1 spacecraft was launched only 29 years ago. It's currently the farthest away from the Earth of any man-made object. In just a short amount of time, this spacecraft, designed by primitive 1970's-era engineers, many of whom were wearing corduroy bell bottoms, has managed to travel so far away from the Earth that it takes radio signals travelling at the speed of light 14 hours to reach it.

I am not making this up. An object that was recently built by people is now far enough away that if you could travel to it at the speed of light, for the in-flight movie you could watch the original director's cut of Water World four times, break for a dinner, and then watch Ishtar before having to put your tray in its upright position.

Light takes four and half years to travel to the nearest star (other than the Sun), 100,000 years to travel across the width of the galaxy, and 100 billion years to travel across the observable Universe.
The speed of light isn't all that fast. Get over it.

Source:internet