Category: Physics

Is Melting exothermic or endothermic? Phases and Phase Transitions Phase Transition Direction of ΔH Fusion (Melting) (solid to liquid) ΔH>0; enthalpy increases (endothermic process) Vaporization (liquid to gas) ΔH>0; enthalpy increases (endothermic process) Sublimation (solid to gas) ΔH>0; enthalpy increases (endothermic process) What are two examples of exothermic? Examples of Exothermic Reactions any combustion reaction. […]

What happens if the solvent line reaches the top of your TLC plate? Once the solvent front reaches to top of the plate, the Rf value can not be determined accurately. If this were to happen, the Rf values from the TLC plate would be different from a TLC plate that was stopped before the […]

What is the important of fuse? A fuse(s) is needed in any electrical system (AC or DC). These protection devices react to the amount of heat being produced by electricity passing through wires and/or components. They are used so as to protect wires and components from the extreme heat produced should there be an electrical […]

How do you describe a noise? Sounds are often described as loud or soft; high-pitched or low-pitched. These words are commonly used to describe, or characterize, how sounds are perceived. Scientists, on the other hand, describe sounds with characteristics that can be measured using instruments. How do you describe a beautiful sound? If you hear […]

What is the correct order of development? (A) Correct sequence in development is Fertilization → Zygote → Cleavage → Morula → Blastula → Gastrula. What are the five stages of man’s development? The key components of Erikson’s model of human development include stage one, infancy, trust versus mistrust; stage two, toddlerhood, autonomy versus shame and […]

What is the characteristics of other planets in the solar system? The solar system is host to two broad categories of planets. The four closest to the sun — Mercury, Venus, Earth and Mars — are the terrestrial planets. They have rocky surfaces enclosed by relatively shallow atmospheres. The gas and ice giants — Jupiter, […]

What is better active or passive noise cancellation? While both passive noise isolation and active noise cancellation allow you to listen to music at lower volumes than earphones without ANC, passive noise isolation is better for your hearing overall. This is because active noise cancellation neutralizes outside noise by creating an equal and opposite noise. […]

What is the Centre of pressure on an aerofoil? Center of Pressure The center of pressure is the point where the total sum of a pressure field acts on a body. In aerospace, this is the point on the airfoil (or wing) where the resultant vector (of lift and drag) acts. What happens to the […]

What are the two main reasons air pressure changes? Although the changes are usually too slow to observe directly, air pressure is almost always changing. This change in pressure is caused by changes in air density, and air density is related to temperature. What are the two factors influencing the movement of air or wind? […]

Can you hear a plane at 20 000 feet? Yes, depending on the type of plane, which would determine how loud it is and what the frequency of its sound output was, in normal cruising flight. How far can you hear a jet? Aircraft noise is also affected by humidity, air density and cloud cover. […]