Category: Physics

What kind of mixture is salt solution and seawater? The salt water described above is homogeneous because the dissolved salt is evenly distributed throughout the entire salt water sample. Often it is easy to confuse a homogeneous mixture with a pure substance because they are both uniform. The difference is that the composition of the […]

What does the body use first for energy? Carbohydrates are used for energy (glucose). Fats are used for energy after they are broken into fatty acids. Protein can also be used for energy, but the first job is to help with making hormones, muscle, and other proteins. Broken down into glucose, used to supply energy […]

What is Joule formula? In equation form: work (joules) = force (newtons) x distance (meters), where a joule is the unit of work, as defined in the following paragraph. In symbols: W = F x d. In practical terms, even a small force can do a lot of work if it is exerted over a […]

Why is it important to have evidence? Evidence is used to back up or refute arguments, and it helps us to make decisions at work. Using evidence allows us to work out what is effective and what is not. Evidence indicates the ideas that are effective and those, which are not meaning that programs are […]

How do you remove a stuck metal lid? Warm water Alternatively, you could fill a bowl with hot water and place the jar upside down in the water, leaving it there for around 30 seconds. The hot water will help expand the metal lid (more so than the glass), making it easier to remove. Does […]

What is SI unit of sound? The SI unit of sound pressure is pascal (Pa). Decibel (dB) is a relative unit of measurement widely used in acoustics. However, the dB is not a unit in the sense that a metre is a unit of length. The decibel is a logarithmic unit used to describe a […]

What happens to the particles when a liquid boils? Boiling. If a liquid is heated the particles are given more energy and move faster and faster expanding the liquid. As the liquid gets warmer more particles have sufficient energy to escape from the liquid. Eventually even particles in the middle of the liquid form bubbles […]

How many seconds does it take to stop a car going 60 mph? 4.5 seconds How long does it take to stop a car at 55 mph? Only then does the car begin to slow. On dry pavement that takes 4 1/2 seconds, traveling another 144 feet, but if it’s wet, you’ll travel 183 feet. […]

How do you use a ray diagram? 1. Pick a point on the top of the object and draw two incident rays traveling towards the mirror. Using a straight edge, accurately draw one ray so that it passes exactly through the focal point on the way to the mirror. Draw the second ray such that […]

What is an inertial frame of reference in physics? Within the realm of Newtonian mechanics, an inertial frame of reference, or inertial reference frame, is one in which Newton’s first law of motion is valid. An inertial frame of reference is one in which the motion of a particle not subject to forces is in […]