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Intro to vectors and scalars

Scalars and vectors are two kinds of quantities that are used in physics and math. Scalars are quantities that only have magnitude (or size), while vectors have both magnitude and direction. Explore some examples of scalars and vectors, including distance, displacement, speed, and velocity. Created by Sal Khan.

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• Is it still a vector if we say "The brick moved 5m towards Sal" even if 'towards Sal' has no specified location.
• As you told towards Sal means you have given a specific direction as Sal is standing in a specific direction so it is a vector quantity
• Does vectors have a location in space? does it vary with time?
This is a question from my Physics textbook. I even couldn't understand the question. Can you explain and answer me?
• A vector stores only two parameters of information - length and direction. It doesn't tell you anything about it's origin/location. It can vary with time if it's given as a function of time, for example if the vector symbolises speed of an accelerating object, then it does vary on time, if the speed is constant then it doesn't vary on time.
• What is the triangle symbol at ?
• The triangle is actually the symbol 'delta', which denotes 'change in'. So delta(t) means change in time.
• What is the difference between distance and displacement?
• Distance is how far you go, displacement is how far you went relative to your starting position! Example: If I walk 2 miles from my house to the grocery store, and walk 2 miles back to my house, my distance traveled is four miles; however my displacement is zero because I'm back where I started.
• A scalar value cannot be a vector because it does no include direction, but can vectors be considered scalar?
• No, for the same reason. But the magnitude (modulus) of a vector is a scalar.
• If people developed the ability to time-travel, would time be a vector or a scalar quantity?
• Being able to travel in a dimension doesn't determine if we use a scalar or vector quantity. The value July 20, 1969, :40 UTC is a scalar time value but 35 minutes from now is a vector.
• O.K. so on earth we can say that an object is going with velocity v(direction North To South). But what I have learned now is that every point in the universe is the centre of universe.
so question 1
Is this true?
question 2
if yes than how will you define direction of a particle. I mean that everywhere you are going in the universe you are at the centre of it.
• Deep questions!

1) Yes, that is a concept from relativity called reference frames. Einstein theorized that the laws of physics should all work no matter what object you think marks the center of the universe, and all experiments up to this point have agreed with him.

2) In a theoretical sense, the vectors you're seeing exist in Euclidean space, which does have a well-identified center (the origin). If someone is doing real-world problems, what you'll find is that they will (usually without mentioning it) assume that there is a standard frame of reference. For instance, if I want to talk about a person running around a circular track, I would assume that the origin is the spot where the person started running. In practice, you'll probably find that it isn't as confusing as you might fear.
• was that ground color yellow or am i colorblind
• It was yellow, a very "ground like color" ...