Category: Physics

What makes online test valid? Validity is arguably the most important criteria for the quality of a test. The term validity refers to whether or not the test measures what it claims to measure. On a test with high validity the items will be closely linked to the test’s intended focus. What makes a test […]

How long can I drive on a bad U-joint? A car with a bad U-joint will break down in a few hundred miles at the maximum. But if you have a bad U-joint and you are having a transmission fluid leakage, you should not drive your car since the U-joint may break down anytime and […]

What happens to water waves when they hit a surface? Water waves can reflect or ‘bounce off’ a surface. For example, waves at sea are reflected when they hit a harbour wall, and waves in washing-up water are reflected off the sides of the sink. Why do water waves travel faster deeper? Wave height stores […]

Is Li2 or Be2 more stable? Be2 Is Stable And Diamagnetic, Bit Li2 Is Unstable. Would Be2+ exist? Be2+ has a bond order of 0.5 and is slightly lower in energy than isolated Be atoms. It will probably exist under special experimental conditions but be unstable. Is Be2 paramagnetic or diamagnetic? Be2 is shown with […]

What was the Karez well system? The Karez Well System is an important ancient irrigation system that is still used in Turpan, Xinjiang, in Northwest China. (Karez is the Uyghur word for ‘well’, from the Persian for ‘channel’.) Locals dug wells and tunnels to transfer water from mountains miles away from their farmland. Why is […]

Does oil get thicker as it warms up? Oil weight, or viscosity, refers to how thick or thin the oil is. Your engine needs oil that is thin enough for cold starts, and thick enough when the engine is hot. Since oil gets thinner when heated, and thicker when cooled, most of us use what […]

Does pressure depend on size? We can see that the force on the surface depends on the size of the surface. However, the pressure is independent of the size of the surface – if we increase the area then we also increase the force, but the pressure remains the same. The SI unit of pressure […]

How do you calculate weight from a load? Take the total weight of the load and divide this by the number of legs supporting the load. For example, assume a 2,000 pound load is to be supported by 2 legs of a sling. The above will give a total minimum weight on each leg of […]

What are the cons of gas? Non-renewable fuel, supply cannot be replaced for millennia. Emits carbon dioxide when burned. Contains 80-95% methane, a potent greenhouse gas (GHG) Explosive, potentially dangerous. Concentrated sources require long distance transmission and transportation. Energy penalties at every stage of production and distribution. What are the side effects of natural gas […]

Is petroleum organic or inorganic? Petroleum is a naturally occurring, flammable liquid found within rock formations in the earth, and is comprised of a mixture of hydrocarbons and other organic compounds. What is origin of crude oil? Crude oil is formed from the remains of dead organisms (diatoms) such as algae and zooplankton that existed […]