Scalar & Vector: Differences & Direction

In summary, scalar quantities are measurements that only have a magnitude or numerical value, while vector quantities have both magnitude and direction. We use +/- signs to specify direction for scalar quantities such as temperature, but this does not necessarily indicate a physical direction.
  • #1
harshinig
1
0
what are the differences between scalar and vector quantities?
why do we use */-in specifying direction of any scalar quantity
 
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  • #2
You should find the answer to this by looking up the definitions of scalar and vector.
The second sentence doesn't make any sense to me. You will see what I mean when you read those definitions!
 
  • #3
I think that the second sentence may be refer to scalar quantities such as temperature, where you can have +10'C but also -10'C.

In a case like this, the signs don't declare the "direction" of the temperature - just its value on a scale with reference to an agreed zero point.
 

1. What is the difference between a scalar and a vector?

A scalar is a physical quantity that has only magnitude (size or amount) and no direction. Examples include mass, temperature, and time. On the other hand, a vector is a physical quantity that has both magnitude and direction. Examples include displacement, velocity, and force.

2. How do you represent a scalar and a vector mathematically?

A scalar is represented by a real number, while a vector is represented by a combination of a magnitude (represented by a real number) and a direction (represented by a unit vector).

3. What is the difference between a scalar and a vector quantity?

A scalar quantity is a physical quantity that can be described by a single number (magnitude), while a vector quantity requires both magnitude and direction to fully describe it.

4. Can a scalar be negative or positive?

Yes, a scalar can be negative, positive, or zero. This is because a scalar only represents the magnitude or size of a physical quantity, and this can take on any value on the number line.

5. How do you determine the direction of a vector?

The direction of a vector is determined by the angle it makes with a reference axis or by using the direction of its components. It is typically measured in degrees or radians and can be represented using a unit vector or by its direction cosines.

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