Worksheet No. 1 Standard : IX Correct The Mistakes Write the sentences correcting the mistakes: 1. Tom doesn't wants to clean his room today.
2. Helen always is talking too much with her friends. 3. The boys play football in the yard yesterday. 4. Who help you to do your homework every day? 5. Tom had helped me to make a kite three days ago. I want this answers
Answers
Answer:
Vector
Those physical quantities which require magnitude as well as direction for their complete representation and follows vector laws are called vectors.
Types of Vector
1. Polar Vectors
These are those vectors which have a starting point or a point of application as a displacement, force etc.
2. Axial Vectors
These are those vectors which represent rotational effect and act along the axis of rotation in accordance with right hand screw rule as angular velocity, torque, angular momentum etc.
Scalars
Those physical quantities which require only magnitude but no direction for their complete representation, are called scalars.
Distance, speed, work, mass, density, etc are the examples of scalars. Scalars can be added, subtracted, multiplied or divided by simple algebraic laws.
Tensors
Tensors are those physical quantities which have different values in different directions at the same point.
Moment of inertia, radius of gyration, modulus of elasticity, pressure, stress, conductivity, resistivity, refractive index, wave velocity and density, etc are the examples of tensors. Magnitude of tensor is not unique.
Different Types of Vectors
(i) Equal Vectors Two vectors of equal magnitude, in same direction are called equal vectors.
(ii) Negative Vectors Two vectors of equal magnitude but in opposite directions are called negative vectors.
(iii) Zero Vector or Null Vector A vector whose magnitude is zero is known as a zero or null vector. Its direction is not defined. It is denoted by 0.
Velocity of a stationary object, acceleration of an object moving with uniform velocity and resultant of two equal and opposite vectors are the examples of null vector.
(iv) Unit Vector A vector having unit magnitude is called a unit vector.
A unit vector in the direction of vector A is given by
 = A / A
A unit vector is unitless and dimensionless vector and represents direction only.
(v) Orthogonal Unit Vectors The unit vectors along the direction of orthogonal axis, i.e., X – axis, Y – axis and Z – axis are called orthogonal unit vectors. They are represented by CBSE Class 11 Physics Notes Vectors
(vi) Co-initial Vectors Vectors having a common initial point, are called co-initial vectors.
(vii) Collinear Vectors Vectors having equal or unequal magnitudes but acting along the same or Ab parallel lines are called collinear vectors.
(viii) Coplanar Vectors Vectors acting in the same plane are called coplanar vectors.
(ix) Localised Vector A vector whose initial point is fixed, is called a localised vector.
(x) Non-localised or Free Vector A vector whose initial point is not fixed is called a non-localised or a free vector.
(xi) Position Vector A vector representing the straight line distance and the direction of any point or object with respect to the origin, is called position vector.
Explanation:
en n the y the hell is striking out of town this week