Category: Physics

What things reduce friction? Silicone aerosols, oils, grease and ball bearings are all used to reduce friction. Air resistance force is the force of air pushing against a moving object. Air resistance (also called drag) is a type of frictional force. Who invented Maglev? Maglev — short for magnetic levitation — trains can trace their […]

Is a line a vector? Vectors are not lines and they have a very different function than lines. A vector is a direction and a magnitude, that’s it. A line, of course, has direction and magnitude, but it also has LOCATION. A vector can be anywhere, but a line exists within space. Can a set […]

Is speed a unit? Speed can be thought of as the rate at which an object covers distance. Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second, but the most common unit of speed in everyday usage is the kilometre per hour or, in the […]

How long does it take to drive 120 miles at 60 mph? It took Joe 2 hours to drive 120 miles at 60 mph, and it took 3 hours at 40 mph, giving us a total time of 5 hours. In the steps above we calculated total distance (120 miles + 120 miles = 240 […]

What is the danger zone for food in degrees? The danger zone is the temperature range in which food-borne bacteria can grow. Food safety agencies, such as the United States’ Food Safety and Inspection Service (FSiIS), define the danger zone as roughly 40 to 140 °F (4 to 60 °C). What kind of salt do […]

What is relation between alpha and gamma? Linear expansion – α Cubical / Volumetric expansion – γ Thus, the relation between linear expansion and cubical expansion is, γ = 3α What is the relation between I and Alpha? Derive the equation, α=i-1n-1. Derive a relation between degree of dissociation and van’t Hoff factor. At start, […]

At what position is valve timing set? Every time we assemble a four stroke engine we have to set the valve timing. It’s quite simple but very important ! Set the engine at Top-Dead-Center (TDC) of the compression stroke, set the timing marks on the cam and you are done. What happens if valve timing […]

What do you mean by dimensional motion? In this lesson, you will learn more about motion in one dimension, meaning that an object is moving in a straight line: either forwards or backwards, up or down, left or right. An example of one-dimensional motion is the motion of the cars in the drag race video. […]

What is the main purpose of the National Electrical Code? The NEC (the National Fire Protection Association’s NFPA 70) is a widely-adopted model code for the installation of electrical components and systems. Its purpose is to safeguard persons and property from hazards arising from the use of electricity (NEC 90.1(A)). What are the two basic […]

What is the difference or similarity of calories and BTUS? A heating calorie is defined as the amount of heat required to raise one gram of water by one degree Celsius. A Btu, or British Thermal Unit, is roughly the amount of heat produced when you burn one match. Technically, a Btu is the amount […]