Question: March 2012 Archives
Wednesday March 28, 2012
When you pump up a bike tire with a bicycle pump, the valve will heat up. Why is that? (If it because of the air passing through the valve, why doesn't the valve heat up when you fill your car tire at the gas station?)
When air is compressed it heas up, so when you use the hand pump, the air is compressed as you go and that heat is passed along to the valve. At the gas station, however, the air has been compressed for hours so the residual heat has already dissapated.
Wednesday March 21, 2012
When an orchestra warms up, the pitch of the wind instruments increases and the pitch of the strings instruments decreases. Why is that?
In both cases, it is because the instrument warms up. The warmth from the player's breath warms the air in the wind instrument and increases the speed of sound, which increases the pitch. With string instruments, the strings expand and slacken slightly, which lowers the pitch.
Wednesday March 14, 2012
- January 2013
- December 2012
- Wed., 12 – Where do butterflies go when it rains?
- November 2012
- October 2012
- September 2012
- August 2012
- July 2012
- Wed., 25 – Can you get sunburn through ordinary glass?
- June 2012
- May 2012
- April 2012
- Wed., 18 – When you take a cake out of the oven, the air inside the oven doesn't burn you, and touching the top of the cake doesn't burn you but touching the metal pan does. If they're all at the same temperature, why is there a difference?
- Wed., 11 – In large lakes, you see can see the water oscillate from side to side. What causes these seiches?
- Wed., 4 – When you pour some liquids such as oil or honey from a distance onto a plate, the stream will start to circle onto the plate. Why does that happen?
- March 2012
- Wed., 28 – When you pump up a bike tire with a bicycle pump, the valve will heat up. Why is that? (If it because of the air passing through the valve, why doesn't the valve heat up when you fill your car tire at the gas station?)
- Wed., 21 – When an orchestra warms up, the pitch of the wind instruments increases and the pitch of the strings instruments decreases. Why is that?
- Wed., 7 – If you place a block of wood in a glass of water, and put that glass in an elevator, will the block float higher in the water as the elevator descends?
- February 2012
- Wed., 29 – The moon experiences the gravitational pull from the earth and the sun, but the sun's pull is twice as powerful as the the earth's. Why then, doesn't the moon get pulled out of our orbit?
- Wed., 22 – When lightening hits a tree, sometimes it scars it, sometimes it blows the bark off and sometimes it blows it up. What accound for those varying effects?
- Wed., 1 – Why does skin dry out in the winter?
- January 2012
- December 2011
- November 2011
- Wed., 23 – If you wear a wind up pocket watch, it will keep good time but if you hang it up, it won't. Why is that?
- Wed., 16 – Cheerios in milk cluster together within a few minutes, even though they were randomly distributed. Why?
- Wed., 9 – If you squeeze a pile of double edged razor blades the sharp edges will look dark. Why is that?
- Wed., 2 – When you drop an icecube into a drink at room temperature, what causes the crackling noise you often hear?
- October 2011
- September 2011
- July 2011
- Wed., 20 – Will black coffee or white coffee stay hotter longer (assuming the milk you added did not lower the temperature)
- Wed., 13 – Swimmers move by pushing and pulling on the water. If the water were more viscous, would they move faster?
- Wed., 6 – When bungee jumping, at what point do you experience the greatest forces and the greatest acceleration?
- June 2011
- Wed., 29 – When you stir a martini, the olive often turns in an opposite direction than the liquid. Why is that?
- Wed., 22 – When you ball up a peice of paper, you can only compress it so far, even though there is still alot of air in the ball. Why can't you compress it further?
- Wed., 15 – If you overhead fan is covered with dust and you turn it on high, why doesn't the dust fly off?
- Wed., 8 – Hot air balloonists say when they are in the air, about half a kilometre up, they can hear what people on the ground are saying. The people on the ground, however, can't hear them.... Why?
- Wed., 1 – A magnetic needle on the surface of water will orient to north, but will not move. The same needle, if placed near a magnet, will orient to North but it will also slide toward the magnet. What's the difference?
- May 2011
- April 2011
- Wed., 27 – Why do tuning forks have two prongs?
- Wed., 20 – Put some ice in the bottom of a test tube, and hold it there with a weight. Add water to the top and then apply heat to the top of the tube. The water at the top can be boiling but the ice will remain at the bottom. Why is that?
- Wed., 6 – When you pour a beer or root beer, you will get a thick head of foam. If you put your finger in it, it will dissipate quickly. What's happening?
- March 2011
- Wed., 16 – If you were at a base camp on the moon, would it be harder or easier to walk on the sidewalk than it is on earth?
- Wed., 9 – Take two wooden pails, without lids, and fill one with hot water and one with cold water and put them outside in freezing weather. Which one will freeze first, and why?
- Wed., 2 – Why is it easier for a male speaker to fill a room with his voice than it is for a female speaker?
- February 2011
- January 2011