Why is it important to center a specimen on low power before attempting on focus on it at high power? When you increase the magnification, you decrease the field of view. Usually, with parfocal microscopes, whatever is in the center of the original field of view is also visible at higher magnification, but if it was off to one side, you probably wouldn't see it at the higher magnification. 4. A student focus on a specimen at low power and carefully centers it before changing to high power.
Experiment: Photoelectric Effect Course Name/Section: Physics 222 Section 012 Date: April 12, 2012 Conclusion The slope of the first order stopping potentials was 0.3753 which yielded an h value of 6.0048x10-34Js, which was 9.38% off of the accepted h value of 6.6x10-34Js. The second order stopping potential’s slope was 0.4255. This yielded an h value of 6.808x10-34Js, which was 2.75% off of the accepted h value. There were many sources of error in this experiment. The percent error is much higher for the first order stopping potential than for the second.
Hair takes on a bleached appearance, while skin becomes darker. Precautions should be taken to limit exposure to ultraviolet light to prevent skin and hair damage. Some of the sun's rays are beneficial, but others, such as ultraviolet rays, are hazardous. This radiation comes in three forms: ultraviolet A (UVA), ultraviolet B (UVB) and ultraviolet C (UVC). The earth's atmosphere filters out UVC radiation, but UVA and UVB affect you every day.
Unfortunately they are not consistent between each other, and that is one of the major endeavors of physics, to find a theory that unifies them both. With E=mc^2 where E is energy, m is mass and c is the speed of light. Because of the equivalence of energy and mass, the energy which an object has due to its motion will add to its mass. In other words, it will make it harder to increase its speed.
The memory is said to be like a photo due to its unchanging nature and high levels of accuracy. The key ingredient to flashbulb memories is a high level of emotional arousal at the time the event was committed to memory. Evidence to support the idea of flashbulb memory comes from Brown and Kulik themselves. They looked at flashbulb memories of the assassination of Martin Luther King. Findings showed that 75~% of black Americans had flashbulb memories of the event compared to only 33% of white Americans.
15 Hz 250 Hz 15 000 Hz 25 000 Hz (1) (b) Why can humans not hear ultrasound? ................................................................................................................................... ................................................................................................................................... (1) (c) The crystal vibrates at a very high frequency. Which is the best description of the frequency of vibration? A The distance the crystal vibrates in a second. B The number of vibrations of the crystal in a second.
Scanning Objective Lens • Most objective lens are color-coded, including scanning objective lenses. Scanning objective lenses usually have a red band around them and provide a magnification of 4x. The purpose of this lens is to provide an initial magnification of the specimen being studied. Although the scanning lens does not provide a great deal of magnification, it is important to use this lens with every specimen to initially bring it into focus and center it within the field of view. Low Power Objective Lens • Low power objective lenses typically provide a 10x magnification and will have a yellow band around them.
Snell's Law In the previous sections we studied light reflecting off various surfaces. What happens when light passes from one medium into another? The speed of light, like that of all waves, is dependent on the medium through which it is travelling. When light moves from one medium into another (for example, from air to glass), the speed of light changes. If the light ray hits the boundary of the new medium (for example the edge of a glass block) at any angle which is not perpendicular to or parallel with the boundary, the light ray will change its direction through the next medium, or appear to `bend'.
How Bright is an Incandescent Light bulb and How Much Energy Does It Require? Brightness is usually measured in a unit call Lumens, Lumens refer to the amount of light
Gas or its inability to escape is what causes volcanos to become violent. The longer gas is trapped, the more pressure builds up. The cause of gas building up is the result of the viscosity of the magma the gas is trapped in. Viscosity is the measure of the flow or how easily a liquid flows. If a liquid is viscous it is thick and will flow slowly like honey whereas a liquid that is nonviscous will flow like water.