# what are vectors?I need the full topic of Vectors and thier sums.

Hinal Srivastava
50 Points
8 years ago
a quantity having direction as well as magnitude, especially as determining the position of one point in space relative to another.is called a vector
Neeti
571 Points
8 years ago
Vector is any quantity which has a magnitude and a direction. It is depicted by an arrow with the arrow head pointing towards the direction of the vector.
Example of a vector would be, force, velocity ( while speed is a scalar, and has magnitude only) , displacement (while distance has magnitude only).

When two vectors A and B are present touching each other at their base, making an angle $\Theta$ with each other,
The magnitude of the resultant is given by

R = (A2 + B2 + 2AB cos$\Theta$)1/2 , and the direction of the resultant R given in terms of angle made by it with one of the vectors is:

tan $\Phi$ = A sin $\Theta$ / B + A cos $\Theta$  where $\Phi$ is the angle between resultant R and vector B.

Please feel free to ask any follow up question and approve the answer if you like it :)
A M S ARUN KRISHNA
216 Points
8 years ago
• To specify some physical quantity magnitude and directions are needed and also obey laws of vector addition is called vector quantity
• Example : displacement,  velocity,  acceleration, weight (5N means magnitude 5 and direction is vertically downwards
• Current does not follow vector addition so it is a scalar quantity