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Showing posts with label Newtons laws. Show all posts
Showing posts with label Newtons laws. Show all posts
Wednesday, January 25, 2012
Tuesday, September 2, 2008
Newton’s Laws of Motion –Study Plan - Session 2
Day 2 Study Plan
5.2 Newton's second law
5.3 Working with Newton's laws
W.O.E. 3 and 4
5.2 Newton's second law
The acceleration of a particle as measured from an inertial frame is given by the (vector) sum of all the forces acting on the particle divided by its mass.
a = F/m or F = ma
Acceleration and force are measured at the same instant. If force becomes zero at an instant, acceleration also becomes zero at the same instant.
5.3 Working with Newton’s First and Second Law
1. Decide the System
We have to assume that forces are acting on a system and the system is at rest or in motion. In this context, the system may be a single particle, a block, a combination of two blocks one kept over the other or two blocks connected by a string etc. But there is a restriction for treating one as a system. All parts of the system should have identical acceleration.
Step 2. Identify the Forces
Once the system is decided, make a list of the forces acting on the system due to all the objects other than the system. Any force applied by the system should not be included in the list of the forces (material from the chapter on forces should help you in deciding various forces exerted by the system and forces exerted by the objects on the system).
Step 3. Make a Free Body Diagram
Represent the system by a point in a separate diagram and draw vectors representing the forces with this point as the common origin
Step 4: Choose axes and Write Equations.
Example 5.2
The example describes a block being pulled by a man with help of a string.
The system under analysis is the block.
It is accelerating in the horizontal direction. So there is net force in the horizontal direction.
It is not accelerating in the vertical direction. Hence net force is vertical direction is zero.
Worked out examples:
3,4,5,
Obective I
3,5, 6,9,10,
Attempt questions in Objective questions (OBJ II)
4
Exercises
1, 2, 3,
5.2 Newton's second law
5.3 Working with Newton's laws
W.O.E. 3 and 4
5.2 Newton's second law
The acceleration of a particle as measured from an inertial frame is given by the (vector) sum of all the forces acting on the particle divided by its mass.
a = F/m or F = ma
Acceleration and force are measured at the same instant. If force becomes zero at an instant, acceleration also becomes zero at the same instant.
5.3 Working with Newton’s First and Second Law
1. Decide the System
We have to assume that forces are acting on a system and the system is at rest or in motion. In this context, the system may be a single particle, a block, a combination of two blocks one kept over the other or two blocks connected by a string etc. But there is a restriction for treating one as a system. All parts of the system should have identical acceleration.
Step 2. Identify the Forces
Once the system is decided, make a list of the forces acting on the system due to all the objects other than the system. Any force applied by the system should not be included in the list of the forces (material from the chapter on forces should help you in deciding various forces exerted by the system and forces exerted by the objects on the system).
Step 3. Make a Free Body Diagram
Represent the system by a point in a separate diagram and draw vectors representing the forces with this point as the common origin
Step 4: Choose axes and Write Equations.
Example 5.2
The example describes a block being pulled by a man with help of a string.
The system under analysis is the block.
It is accelerating in the horizontal direction. So there is net force in the horizontal direction.
It is not accelerating in the vertical direction. Hence net force is vertical direction is zero.
Worked out examples:
3,4,5,
Obective I
3,5, 6,9,10,
Attempt questions in Objective questions (OBJ II)
4
Exercises
1, 2, 3,
Sunday, August 31, 2008
Newton’s Laws of Motion - Study Plan - Session - 1
5.1 First law of motion (From HC Verma Part 1)
Study Plan
Day 1
5.1 First law of motion
-----------------------
Points to be remembered
First law of motion
If the (vector) sum of all the forces acting on a particle is zero then and only then the particle remains unaccelerated (i.e., remains at rest or moves with constant velocity).
We can say in vector notation
a = 0 if and only if resultant force F = 0
A frame of reference in which Newton's first law is valid is called an inertial frame of reference.
A frame of reference in which Newton's first law is not valid is called a noninertial frame of reference. (Example: lamp in an elevator cabin whose cable had broken)
Example of lamp in an elevator whose cable had broken:
In the cabin when one measures with reference to the cabin, the lamp hanging from the ceiling has no acceleration. Hence the forces acting on the lamp, its weight (W) and the tension in the string supporting it are balancing each other. We can infer that W = T.
But for an observer on the ground, lamp is accelerating with acceleration g, when he considers the forces acting on the lamp as W and T once again, W is not equal to T as lamp is acceleating. Both cannot be right at the same time, and it means in one of the frames Newton's first law is not applicable.
Inertial frame: Hence inertial frame is a frame of reference in which Newton's first law is valid.
Is earth an inertial frame of reference?
Strictly it is not. But as a good approximation, earth can be taken as an inertial frame of reference.
All frames moving uniformly with respect to an inertial frame are themselves inertial.
This relation was derived from the relation that converts acceleration with respect to one frame into acceleration with respect to another frame. When the other frame is moving with uniform velocity it acceleration with respect to the frame in reference is zero.
Examples: A train moving with uniform velocity with respect to ground, a plane flying with uniform velocity with respect to a high etc. The sum of forces acting on a suit case kept on the shelves of them with turnout to be zero.
Concepts covered in the session
First law of motion
Frames of reference (concept from Chapter 3)
Inertial frame of reference
noninertial frame of reference
Inertial frames other than earth (frames moving with uniform velocity w.r.t earth)
Example 5.1 deals with forces acting on heavy particle hanging from a string fixed with the roof. the particle is stationery. The forces acting are pull of the earth downward due to gravity and pull of the string vertically upward.
Go through examples in worked out examples
1.
2.
Attempt questions in Objective questions (OBJ I)
1.
5.
Attempt questions in Objective questions (OBJ II)
1.
2.
3.
Study Plan
Day 1
5.1 First law of motion
-----------------------
Points to be remembered
First law of motion
If the (vector) sum of all the forces acting on a particle is zero then and only then the particle remains unaccelerated (i.e., remains at rest or moves with constant velocity).
We can say in vector notation
a = 0 if and only if resultant force F = 0
A frame of reference in which Newton's first law is valid is called an inertial frame of reference.
A frame of reference in which Newton's first law is not valid is called a noninertial frame of reference. (Example: lamp in an elevator cabin whose cable had broken)
Example of lamp in an elevator whose cable had broken:
In the cabin when one measures with reference to the cabin, the lamp hanging from the ceiling has no acceleration. Hence the forces acting on the lamp, its weight (W) and the tension in the string supporting it are balancing each other. We can infer that W = T.
But for an observer on the ground, lamp is accelerating with acceleration g, when he considers the forces acting on the lamp as W and T once again, W is not equal to T as lamp is acceleating. Both cannot be right at the same time, and it means in one of the frames Newton's first law is not applicable.
Inertial frame: Hence inertial frame is a frame of reference in which Newton's first law is valid.
Is earth an inertial frame of reference?
Strictly it is not. But as a good approximation, earth can be taken as an inertial frame of reference.
All frames moving uniformly with respect to an inertial frame are themselves inertial.
This relation was derived from the relation that converts acceleration with respect to one frame into acceleration with respect to another frame. When the other frame is moving with uniform velocity it acceleration with respect to the frame in reference is zero.
Examples: A train moving with uniform velocity with respect to ground, a plane flying with uniform velocity with respect to a high etc. The sum of forces acting on a suit case kept on the shelves of them with turnout to be zero.
Concepts covered in the session
First law of motion
Frames of reference (concept from Chapter 3)
Inertial frame of reference
noninertial frame of reference
Inertial frames other than earth (frames moving with uniform velocity w.r.t earth)
Example 5.1 deals with forces acting on heavy particle hanging from a string fixed with the roof. the particle is stationery. The forces acting are pull of the earth downward due to gravity and pull of the string vertically upward.
Go through examples in worked out examples
1.
2.
Attempt questions in Objective questions (OBJ I)
1.
5.
Attempt questions in Objective questions (OBJ II)
1.
2.
3.
Wednesday, May 7, 2008
Concept Review - Chapter 5 Newton's Laws of Motion
(This revision material will be meaningful and useful only when you have read HC Verma's Chaper)
First law of motion
If the (vector) sum of all the forces acting on a particle is zero then and only then the particle remains unaccelerated (i.e., remains at rest or moves with constant velocity).
We can say in vector notation
a = 0 if and only if resultant force F = 0
A frame of reference in which Newton's first law is valid is called an inertial frame of reference.
A frame of reference in whch Newton's first law is not valid is called a noninertial frame of reference. (Example: lamp in an elevator cabin whose cable had broken)
Example of lamp in an elevator who cable had broken:
In the cabin when on measures with reference to the cabin, the lamp hanging from the ceiling has no acceleration. Hence the forces acting on the lamp, its weight (W) and the tension in the string supporting it are balancing each other W = T.
But for an observer on the ground, lamp is accelerating with acceleration g, when he considers the forces acting on the lamp as w and T once again, W is not equal to T as lamp is accelarating. Both cannot be right at the same time, and it means in once of the frames Newton's first law is not applicable.
Interial frame
All frames moving uniformly with respect to an inertial frame are themselves inertial.
Examples: A train moving with uniform velocity with respect to ground, a plane flying with uniform velocity with respect to a high etc. The sum of forces acting on a suit case kept on the shelves of them with turnout to be zero.
Second law of motion
The acceleration of a particle as measured from an inertial frame is given by the (vector) sum of all the forces acting on the particle divided by its mass.
a = F/m or F = ma
Acceleration and force are measured at the same instant. If force becomes zero at an instant, acceleation also becomes zero at the same instant.
Third law of motion
Psuedo forces
Inertia
First law of motion
If the (vector) sum of all the forces acting on a particle is zero then and only then the particle remains unaccelerated (i.e., remains at rest or moves with constant velocity).
We can say in vector notation
a = 0 if and only if resultant force F = 0
A frame of reference in which Newton's first law is valid is called an inertial frame of reference.
A frame of reference in whch Newton's first law is not valid is called a noninertial frame of reference. (Example: lamp in an elevator cabin whose cable had broken)
Example of lamp in an elevator who cable had broken:
In the cabin when on measures with reference to the cabin, the lamp hanging from the ceiling has no acceleration. Hence the forces acting on the lamp, its weight (W) and the tension in the string supporting it are balancing each other W = T.
But for an observer on the ground, lamp is accelerating with acceleration g, when he considers the forces acting on the lamp as w and T once again, W is not equal to T as lamp is accelarating. Both cannot be right at the same time, and it means in once of the frames Newton's first law is not applicable.
Interial frame
All frames moving uniformly with respect to an inertial frame are themselves inertial.
Examples: A train moving with uniform velocity with respect to ground, a plane flying with uniform velocity with respect to a high etc. The sum of forces acting on a suit case kept on the shelves of them with turnout to be zero.
Second law of motion
The acceleration of a particle as measured from an inertial frame is given by the (vector) sum of all the forces acting on the particle divided by its mass.
a = F/m or F = ma
Acceleration and force are measured at the same instant. If force becomes zero at an instant, acceleation also becomes zero at the same instant.
Third law of motion
Psuedo forces
Inertia
Friday, February 8, 2008
IIT JEE Physics Formula Revision 5. Newtons law of motion
1. Acceleration vectoS a(P,S) = Acceleration vector a(P,S') if S is an inertial frame and S' is a frame moving uniformly with respect to S.
Tuesday, October 23, 2007
Study guide H C Verma JEE Physics Ch. 5 NEWTON'S LAWS OF MOTION
Newton’s laws of motion;
--------------
Main Sections
5.1 Newton's First law
5.2 Newton's second law
5.3 Working with Newton's laws
5.4 Newton's third law of motion
5.5 Pseudo forces
5.6 The Horse and the cart
5.7 Inertia
---------------------
Subsections under each main section
5.1 First law of motion
Inertial frames other than earth
5.2 Newton's second law
5.3 Working with Newton's laws
5.4 Newton's third law of motion
5.5 Pseudo forces
5.6 The Horse and the cart
5.7 Inertia
------------
Study Plan
Day 1
5.1 First law of motion
Example 5.1
W.O.E. 1 and 2
http://iit-jee-physics.blogspot.com/2008/08/newtons-laws-of-motion-study-plan.html
Day 2
5.2 Newton's second law
5.3 Working with Newton's laws
W.O.E. 3 and 4
Points to be noted
http://iit-jee-physics.blogspot.com/2008/09/newtons-laws-of-motion-study-plan.html
Day 3
5.4 Newton's third law of motion
W.O.E. 5,6
Day 4
5.5 Pseudo forces
W.O.E. 7,8
Day 5
5.6 The Horse and the cart
5.7 Inertia
W.O.E. 9,10,11
Day 6
Chapter 5
Objective I
Day 7
Chapter 5
Objective II
Day 8
Chapter 5
Exercises 1 to 5
Day 9
Chapter 5
Exercises 6 to 10
Day 10
Chapter 5
Exercises 11 to 15
Day 11
Chapter 5 Revision
Exercises 16 to 18
Day 12
Chapter 5 Revision
Exercises 19 to 21
Day 13
Chapter 5 Revision
Exercises 22 to 24
Day 14
Chapter 5 Revision
Exercises 25 to 27
Day 15
Chapter 5 Revision
Exercises 28 to 30
Day 16
Chapter 5 Revision
Exercises 31 to 33
Day 17
Chapter 5 Revision
Exercises 34 to 36
Day 18
Chapter 5 Revision
Exercises 37 to 39
Day 19
Chapter 5 Revision
Exercises 40 to 42
Day 20
Chapter 5 Revision
Attempt Questions for short Answer 1 to 17
Audiovisual lecture
Newton's first law
http://www.curriki.org/nroc/Introductory_Physics_1/lesson03/Container.html
Newton's second law
http://www.curriki.org/nroc/Introductory_Physics_1/lesson04/Container.html
Newton's thrid law
http://www.curriki.org/nroc/Introductory_Physics_1/lesson05/Container.html
Newton's laws - applications
http://www.curriki.org/nroc/Introductory_Physics_1/lesson06/Container.html
Websites
plasma4.sr.unh.edu/ng/phys407/phys407-6-23-05.pdf
-----------------
JEE Question 2007 Paper II
Statement - 1
A cloth covers a table. Some dishes are kept on it. The cloth can be pulled out without dislodging the dishes from the table.
Because
Statement - 2
For every action there is an equal an opposite reaction.
(A) Statement – 1 is True, Statement – 2 is True; Statement – 2 is a correct explanation for statement – 1
(B) Statement – 1 is True, Statement – 2 is True; Statement – 2 is Not a correct explanation for Statement – 1.
(C) Statement – 1 is True, Statement – 2 is False
(D) Statement – 1 is False, Statement – 2 is True
Correct choice: (B)
S1 is correct.
S2 is also correct but it does not explain S1. S1 is possible because of inertia.
-----------------------
---------
JEE Question 2007 Paper I
Two particles of mass m each are tied at the ends of a light string of
length 2a. The whole system is kept on a frictionless horizontal surface
with the string held tight so that each mass is at a distance ‘a’ from the
centre P (as shown in the figure. *figure not given in this post). Now, the mid-point of the string is pulled vertically upwards with a small but constant force F. As a result,the particles move towards each other on the surface. The magnitude of
acceleration, when the separation between them becomes 2x, is
(A) (F/2m)(a/SQRT(a^2-x^2))
(B) (F/2m)(x/SQRT(a^2-x^2))
(C) (F/2m)(x/a)
(D) (F/2m)(SQRT(a^2-x^2)/x)
Solution: B
Imagine the string being pulled upward from midpoint, but only horizontal movement is there.Assume that the string makes with the horizontal surface is θ (theta) , and the tension in the string is T.
F = 2Tsinθ (Tension in each side of the string)
Force in the horintal direction on each particle = F' = ma = T Cosθ
So a = T Cosθ/m
T = F/2Sinθ
a = (F/2m)cotθ
In the triange formed between half of the string and horizontal surface,and the imaginary vertical line through which force is being applied, diagonal is half of the string hence a, and the horizontal side is x. The third side is SQRT(a^2-x^2)
Hence cotθ = x/SQRT(a^2-x^2)
a = (F/2m)(x/SQRT(a^2-x^2))
---------------------
--------------
Main Sections
5.1 Newton's First law
5.2 Newton's second law
5.3 Working with Newton's laws
5.4 Newton's third law of motion
5.5 Pseudo forces
5.6 The Horse and the cart
5.7 Inertia
---------------------
Subsections under each main section
5.1 First law of motion
Inertial frames other than earth
5.2 Newton's second law
5.3 Working with Newton's laws
5.4 Newton's third law of motion
5.5 Pseudo forces
5.6 The Horse and the cart
5.7 Inertia
------------
Study Plan
Day 1
5.1 First law of motion
Example 5.1
W.O.E. 1 and 2
http://iit-jee-physics.blogspot.com/2008/08/newtons-laws-of-motion-study-plan.html
Day 2
5.2 Newton's second law
5.3 Working with Newton's laws
W.O.E. 3 and 4
Points to be noted
http://iit-jee-physics.blogspot.com/2008/09/newtons-laws-of-motion-study-plan.html
Day 3
5.4 Newton's third law of motion
W.O.E. 5,6
Day 4
5.5 Pseudo forces
W.O.E. 7,8
Day 5
5.6 The Horse and the cart
5.7 Inertia
W.O.E. 9,10,11
Day 6
Chapter 5
Objective I
Day 7
Chapter 5
Objective II
Day 8
Chapter 5
Exercises 1 to 5
Day 9
Chapter 5
Exercises 6 to 10
Day 10
Chapter 5
Exercises 11 to 15
Day 11
Chapter 5 Revision
Exercises 16 to 18
Day 12
Chapter 5 Revision
Exercises 19 to 21
Day 13
Chapter 5 Revision
Exercises 22 to 24
Day 14
Chapter 5 Revision
Exercises 25 to 27
Day 15
Chapter 5 Revision
Exercises 28 to 30
Day 16
Chapter 5 Revision
Exercises 31 to 33
Day 17
Chapter 5 Revision
Exercises 34 to 36
Day 18
Chapter 5 Revision
Exercises 37 to 39
Day 19
Chapter 5 Revision
Exercises 40 to 42
Day 20
Chapter 5 Revision
Attempt Questions for short Answer 1 to 17
Audiovisual lecture
Newton's first law
http://www.curriki.org/nroc/Introductory_Physics_1/lesson03/Container.html
Newton's second law
http://www.curriki.org/nroc/Introductory_Physics_1/lesson04/Container.html
Newton's thrid law
http://www.curriki.org/nroc/Introductory_Physics_1/lesson05/Container.html
Newton's laws - applications
http://www.curriki.org/nroc/Introductory_Physics_1/lesson06/Container.html
Websites
plasma4.sr.unh.edu/ng/phys407/phys407-6-23-05.pdf
-----------------
JEE Question 2007 Paper II
Statement - 1
A cloth covers a table. Some dishes are kept on it. The cloth can be pulled out without dislodging the dishes from the table.
Because
Statement - 2
For every action there is an equal an opposite reaction.
(A) Statement – 1 is True, Statement – 2 is True; Statement – 2 is a correct explanation for statement – 1
(B) Statement – 1 is True, Statement – 2 is True; Statement – 2 is Not a correct explanation for Statement – 1.
(C) Statement – 1 is True, Statement – 2 is False
(D) Statement – 1 is False, Statement – 2 is True
Correct choice: (B)
S1 is correct.
S2 is also correct but it does not explain S1. S1 is possible because of inertia.
-----------------------
---------
JEE Question 2007 Paper I
Two particles of mass m each are tied at the ends of a light string of
length 2a. The whole system is kept on a frictionless horizontal surface
with the string held tight so that each mass is at a distance ‘a’ from the
centre P (as shown in the figure. *figure not given in this post). Now, the mid-point of the string is pulled vertically upwards with a small but constant force F. As a result,the particles move towards each other on the surface. The magnitude of
acceleration, when the separation between them becomes 2x, is
(A) (F/2m)(a/SQRT(a^2-x^2))
(B) (F/2m)(x/SQRT(a^2-x^2))
(C) (F/2m)(x/a)
(D) (F/2m)(SQRT(a^2-x^2)/x)
Solution: B
Imagine the string being pulled upward from midpoint, but only horizontal movement is there.Assume that the string makes with the horizontal surface is θ (theta) , and the tension in the string is T.
F = 2Tsinθ (Tension in each side of the string)
Force in the horintal direction on each particle = F' = ma = T Cosθ
So a = T Cosθ/m
T = F/2Sinθ
a = (F/2m)cotθ
In the triange formed between half of the string and horizontal surface,and the imaginary vertical line through which force is being applied, diagonal is half of the string hence a, and the horizontal side is x. The third side is SQRT(a^2-x^2)
Hence cotθ = x/SQRT(a^2-x^2)
a = (F/2m)(x/SQRT(a^2-x^2))
---------------------
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