QUES: Sound waves are mechanical waves. They can travel only through matter. They cannot travel through empty space. This was demonstrated in the 1600s by a scientist named Robert Boyle. Boyle placed a ticking clock in a sealed glass jar. The clock could be heard ticking through the air and glass of the jar. Then Boyle pumped the air out of the jar. The clock was still running, but the ticking could not be heard. Thats because the sound couldnt travel without air particles to transfer the sound energy. Is there any other place where sound cannot be heard? Here is a hint: is there any other place that does not have air molecules? Thats right, in space sound cannot be transferred. So can astronauts hear each other? Yes, they can, because they are in enclosed space stations or pressurized suits.In both cases, they are surrounded by air molecules. If they left their space ship and did not use their electronics, they would not be able to hear each other. Next time you watch a science fiction movie, think about this factoid. When spaceships are destroyed by hostile alien beings, there would be no sound heard. Sound waves can travel through many kinds of matter.
Do you have any questions?
MY QUESTION: In Boyle's experiment, what did he do to make the clock stop being heard while in the jar?

QUES: If you build a campfire, you start with a large stack of sticks and logs. As the fire burns, the stack slowly shrinks. By the end of the evening, all that is left is a small pile of ashes. What happened to the matter that you started with? Was it destroyed by the flames? It may seem that way. What do you think happened? The truth is that the same amount of matter still exists. The wood changed not only to ashes, but also to carbon dioxide, water vapor, and other gases. The gases floated off into the air, leaving behind just the ashes. Although matter was changed, it was not created or destroyed. Because the same amount of matter still exists, we can say that matter is conserved. You may wonder how it can be conserved if something is now missing? Assume you had measured the mass of the wood before you burned it. Assume you had also trapped the gases released by the burning wood and measured their mass and the mass of the ashes. What would you find? The ashes and gases combined have the same mass as the wood you started with. This example illustrates the law of conservation of mass.
Do you have any questions?
MY QUESTION: How is matter conserved after wood burns?

QUES: American Airlines Flight 11: FAA Awareness. Although the Boston Center air traffic controller realized at an early stage that there was something wrong with American 11, he did not immediately interpret the plane's failure to respond as a sign that it had been hijacked. At 8:14, when the flight failed to heed his instruction to climb to 35,000 feet, the controller repeatedly tried to raise the flight. He reached out to the pilot on the emergency frequency. Though there was no response, he kept trying to contact the aircraft. At 8:21, American 11 turned off its transponder, immediately degrading the information available about the aircraft. The controller told his supervisor that he thought something was seriously wrong with the plane, although neither suspected a hijacking. The supervisor instructed the controller to follow standard procedures for handling a "no radio" aircraft. The controller checked to see if American Airlines could establish communication with American 11. He became even more concerned as its route changed, moving into another sector's airspace. Controllers immediately began to move aircraft out of its path, and asked other aircraft in the vicinity to look for American 11. At 8:24:38, the following transmission came from American 11: American 11: We have some planes. Just stay quiet, and you'll be okay. We are returning to the airport. The controller only heard something unintelligible; he did not hear the specific words "we have some planes." The next transmission came seconds later: American 11: Nobody move. Everything will be okay. If you try to make any moves, you'll endanger yourself and the airplane.
Do you have any questions?
MY QUESTION: When The supervisor instructed the controller to follow standard procedures for handling a "no radio" aircraft what further steps by America 11 alarmed them?

QUES: Porky is looking all over the big city for a hotel room , but due to a convention there are no vacancies . Porky takes the only available vacancy at one hotel , but will have to share with Daffy Duck , who is a very loud , obnoxious and annoying sort . Daffy introduces his invisible kangaroo friend '' Hymie '' , but Porky wo n't believe that . Daffy spends the rest of the night annoying Porky : pestering him with questions , shaking the bed , spilling water from a glass , hogging the blanket and finally literally sending the both of them flying off the bed when Daffy kicks , and startles , Porky with his literally frozen feet . Fed up with his antics , Porky stuffs Daffy in a pillow case and drops him out of the window . As Porky goes back to bed , Daffy returns bandaged , but shakes them off and prepares to get revenge . Daffy tricks the half-asleep pig into stepping out of a window thinking he 's boarding a train . Daffy hides the window saying it 's '' too gruesome '' to watch . Suddenly he hears train noises , and behind the shade , sees the still-drowsy Porky pulling away on an actual train and waving at Daffy . Daffy finds this silly . Then he bounces all around the room , '' Hoo-Hoo ! '' - ing wildly .
Do you have any questions?
MY QUESTION:
What is too gruesome to watch