Category: Physics

How long do rechargeable batteries last if not used? two to three year How do I know if my rechargeable batteries are still good? Yes – just check the cell voltage. NiMH are fully discharged at ~1V, so if any of your cells are going down to this quickly (after a few cycles) then they’re […]

What are examples of ratio variables? Examples of ratio variables include: enzyme activity, dose amount, reaction rate, flow rate, concentration, pulse, weight, length, temperature in Kelvin (0.0 Kelvin really does mean “no heat”), survival time. What are the 5 most common process variables? The most common process variables fall into five major types: level, flow, […]

What is the charge for calcium ion? 2 What type of ion does calcium form? Calcium, Ca Calcium is also in Group 2. It has two electrons in its outer shell. When these electrons are lost, a calcium ion, Ca 2+, is formed. A calcium ion has the same electronic structure as an argon atom […]

What is a good weight to curl? According to Weis, men up to 120 pounds should be able to curl 70 pounds; men 121 to 135 pounds should be able to lift 85 pounds; men 136 to 155 pounds should ideally lift 105; men 156 to 170 pounds should lift 120 pounds; men 171 to […]

Where is UV found? UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. What is UV color? UV light has a shorter wavelength than visible light. […]

Why does oil make a rainbow in water? Most often seen in recently made puddles on the sides of roads, the oil refracts light much the same way a rainbow does. Simply put, the thin layer of oil floating on top of the water refracts the light which then bounces back up off the water […]

What do you mean by C * * * * * * * * * Frequency? Technically, a cumulative frequency distribution is the sum of the class and all classes below it in a frequency distribution. All that means is you’re adding up a value and all of the values that came before it. Cumulative […]

How do muscles get oxygen? Oxygen is supplied to the muscles via red blood cells. Red blood cells carry hemoglobin which oxygen bonds with as the hemoglobin rich blood cells pass through the blood vessels of the lungs. The now oxygen rich blood cells carry that oxygen to the cells that are demanding it, in […]

What are the causes and effects of eutrophication? “Eutrophication is an enrichment of water by nutrient salts that causes structural changes to the ecosystem such as: increased production of algae and aquatic plants, depletion of fish species, general deterioration of water quality and other effects that reduce and preclude use”. What can humans do to […]

Is tens AC or DC? A standard TENS unit typically delivers a low-frequency (<50 Hz) alternating current to a focused treatment area. Due to the nature of low-frequency, however, these signals have a low capacity to overcome skin resistance – resulting in these units only providing pain relief via the Gate Control Theory while being […]