Physics Lab ManualNCERT Solutions Class 11 Physics Sample Papers
Scalar and vector quantities
Physical quantities, having only magnitude, are called scalar quantities or scalars. Examples : Distance, speed, mass, etc.
Physical quantities, having both magnitude and direction and obey vector algebra are called vector quantities or vectors.
Examples : Displacement, velocity, weight, etc.
Geometrical vector and its representation
A geometrical vector is a straight line with an arrow at one end called tip (or head), the other end is called tail. This arrow represents a vector quantity.
The length of the line represents the magnitude of the vector quantity on some chosen scale.
Addition of vectors
Combining the effect of many simultaneous vectors into a single vector is called addition or composition of vectors. The single vector so obtained, is called resultant of the many vectors. The many added vectors, are called the components of the single vector.
Parallelogram law of addition o two vectors
Statement. If two vectors acting simultaneously on a particle be represented in magnitude and direction by the two adjacent sides of a parallelogram drawn from a point, then their resultant is completely represented in magnitude and direction by the diagonal of that parallelogram drawn from that point.
Triangle law of addition of two vectors
Statement. If two vectors acting simultaneously on a particle be represented in magnitude and direction by the two sides of a triangle taken in same order, then their resultant will be completely represented in magnitude and direction by the third side of the triangle taken in the opposite order.
Equilibrium of vectors and equilibrant vector
Two or more vectors are said to be in equilibrium if their resultant is zero. In this case, each single vector balances the other remaining vectors.
A single vector which balances other vectors, is called an equilibrant of other vectors. It must be equal and opposite of the resultant of other vectors.