Motion In A Plane: Class 11 Physics NCERT Chapter 4

Key Features Of NCERT Material for Class 11 Science Chapter 4  – Motion In A Plane

In the last chapter 3, you learned about Motion In A Straight Line. In this chapter, you will be learning about Motion in a Plane.

Quick revision notes

• Motion in a plane is called as movement in two measurements e.g., shot movement, roundabout movement and so on. For the examination of such movement our reference will be made of an inception and two co-ordinate tomahawks X and Y.
• Scalar and Vector Quantities 

Scalar Quantities. The physical amounts which are totally indicated by their size or size alone are called scalar amounts. 

Models. Length, mass, thickness, speed, work, and so forth. 

Vector Quantities. Vector amounts are those physical amounts which are described by both size and bearing. 

Models. Speed, dislodging, increasing speed, power, force, force and so forth. 

• Characteristics of Vectors 

Following are the qualities of vectors: 

(I) These have both extent and bearing. 

(ii) These don’t comply with the conventional laws of Algebra. 

(iii) These alter if either greatness or course or both change. 

(iv) These are spoken to by shameless letters or letters having bolt over them. 

• Unit Vector 

A unit vector is a vector of unit size and focuses a specific way. It is utilized to indicate the heading as it were. Unit vector is spoken to by putting a top (^) over the amount. 

• Equal Vectors
• Zero Vector
• Negative of a Vector
• Parallel Vectors
• Coplanar Vectors

Vectors are supposed to be coplanar in the event that they lie in a similar plane or they are corresponding to a similar plane, else they are supposed to be non-coplanar vectors. 

• Displacement Vector

The dislodging or displacement vector is a vector which gives the situation of a point concerning a point other than the cause of the co-ordinate framework.

• Parallelogram Law of Vector Addition

In the event that two vectors, acting at the same time at a point, can be spoken to both in size and course by the two adjoining sides of a parallelogram drawn from a point, at that point the resultant is spoken to totally both in size and heading by the inclining of the parallelogram going through that point. 

• Triangle Law of Vector Addition

In the event that two vectors are spoken to both in size and bearing by the different sides of a triangle taken in a similar request, at that point the resultant of these vectors is spoken to both in size and heading by the third side of the triangle taken in the contrary request. 

• Polygon Law of Vector Addition

On the off chance that various vectors are spoken to both in size and heading by the sides of a polygon taken in a similar request, at that point the resultant vector is spoken to both in greatness and course by the end side of the polygon taken in the contrary request. 

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• Properties of Vector Addition

Vector addition has following properties:

• Resolution of Vectors

It is a cycle of parting a solitary vector into at least two vectors in various ways which together produce a similar impact as is created by the single vector alone. The vectors into which the given single vector is splitted are called part of vectors. Indeed, the goal of a vector is only inverse to organization of vectors. 

In the event that the parts of a given vector are opposite to one another, at that point they are called rectangular segments. 

• Position Vector
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• Multiplication of Vectors

(i) Scalar item (Dot item). Scalar result of two vectors is characterized as the result of the size of two vectors with cosine of littler edge between them. 

• Properties of Scalar Product
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• Properties of Cross Product
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• Lami’s Theorem

Lami’s hypothesis states, “If a molecule under the concurrent activity of three powers is in balance, at that point each power has a consistent proportion with the sine of the edge between the other two powers.” 

 

• Projectile Motion

The shot is an overall name given to an item that is given an underlying slanted speed and which in this manner follows a way dictated by the gravitational power following up on it and by the frictional opposition of the air. The way followed by a shot is called its direction. 

Condition of shot movement. The overall instance of shot movement relates to that of an article that has been given an underlying speed u at some point 8 above (or beneath) the flat. The even and vertical removals x and y are given by 

• Angular Displacement

Precise removal of the item moving around a roundabout way is characterized as the edge followed out by the span vector at the focal point of the round way in a given time. 

θ (point) = bend/sweep 

θ — > the greatness of precise uprooting. It is communicated in radians (rad). 

• Angular Velocity

Angular velocity of an object in circular motion is defined as the time rate of change of its angular displacement.

• Angular Acceleration

Precise speed of an article in roundabout movement is characterized as the time pace of progress of its rakish relocation.

• Uniform Circular Motion

At the point when a body moves in a roundabout way with a steady speed, at that point the movement of the body is known as uniform roundabout movement. 

The time taken by the item to finish one upheaval on its round way is called timespan. For round movement, the quantity of unrests finished per unit time is known as the recurrence (v). Unit of recurrence is 1 Hertz (1 Hz). It is discovered that 

• Centripetal Acceleration

To keep up a molecule in its uniform roundabout movement a radially internal increasing speed ought to be ceaselessly kept up. It is known as the centripetal speeding up.

• IMPORTANT TABLES
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