Mr.+Nieman's+House+of+physics

Ursuline Academy Welcome to Mr. Nieman's House of Physics. I plan to use this page to provide all of you with educational websites that I use in my instruction. I am a physics teacher at Ursuline Academy in Blue Ash, OH.

[|PhET demonstrations] [|Star Wars] - If you watch any Star Wars movie, you see the starships flying by one another and hear the roar of their engines and the pulsating sound of laser cannons. The truth is, in space, you wouldn't hear the engines OR the lasers...in fact you wouldn't hear anything. Sound is a mechanical wave. It needs a medium to travel through. Space is a vacuum. There is no matter present. Since there is no medium, there is no way for a sound wave to move from its source. You would not be able to hear anything as a result because it couldn't reach your ship.
 * bad science:**

Probe: Making Sound pages 43-47 //Uncovering Student Ideas in Science//

[|Indiana Jones: Nuke the Fridge] I hate to pick on George Lucas, but in the movie, Indiana Jones and the Kingdom of the Crystal Skull, could be the standard by which all bad science in film is judged. This movie is full moments that left me, as a physics teacher, shaking my head. My favorite //bad science// moment has to be when Indiana Jones unwittingly ends up in a fake town that has been constructed to be destroyed by a nuclear bomb test. Jones runs around as the countdown starts, frantically looking for a way to get out. He finally decides, at the last minute to jump into a lead-lined refrigerator. As the bomb goes off, we see the refrigerator flying through the air, going several miles and then ending up crashing on the desert floor where Indy emerges unscathed. The problem with this is that Jones would have been killed by the impact of the fridge hitting the ground. Impulse is a physics term used in collisions relating an object's impact force to the time the object is in contact with the force. The product of these two is the object's impulse. This, in turn, is equal to the object's change in momentum. Momentum is the product of an objects mass x velocity. When an object stops moving, it's final momentum is zero, regardless of how it stops. The main thing that determines the amount of force you will feel in a collision depends on how long the force takes you stop youUv. If you throw an egg at a brick wall, it will break. If you throw an egg at the same speed at a sheet, it won't break. If it is thrown at the same velocity, the change in momentum for the egg is the same in both cases. Therefore their impulses are also equal. The difference is in the time it takes to stop the egg. In the case of the wall, the egg stops in a very smalll amount of time, so the the force must be great. When it hits the sheet, however, the contact time is longer, so the impact force has to be smaller since both impulses would be the same. The moral of the story then is that greater contact time means less impact force. Given that Jones' fridge was traveling at an extremely high rate of speed and was stopped immediately, there was not enough padding in the fridge to slow his motion enough to make the force anything less than a lethal force....in fact a force that would reduce him to bloodied and crushed mass of flesh. Side note: This science is SO BAD that this scene has a whole new meaning. They used to say that if a television show or movie series had gotten to a point where it was going bad, it was said to have Jumped the Shark (look that up). Now they say it has NUKED THE FRIDGE!

Probe: Force and Motion Ideas pages 79-82 //Uncovering Student Ideas in Physical Science Volume 1//