Gravity

Question:

Near to the point where I am standing on the surface of Planet X, the gravitational force on a mass m is vertically down but has magnitude myy2 where y is a constant and y is the mass's height above the horizontal ground. (a) Find the work done by gravity on a mass m moving from r1 to r2, and use your answer to show that gravity on Planet X, although most unusual, is still conservative. Find the corresponding potential energy. (b) Still on the same planet, I thread a bead on a curved, frictionless, rigid wire, which extends from ground level to a height h above the ground. Show clearly in a picture the forces on the bead when it is somewhere on the wire. (Just name the forces so it's clear what they are; don't worry about their magnitude.) Which of the forces are conservative and which are not? (c) If I release the bead from rest at a height h, how fast will it be going when it reaches the ground?

Solution:

Fluid Statics

Question:

What force must be exerted through the bolts to hold the dome in place? The metal dome and pipe weigh 6 kN. The dome has no bottom. Here ℓ = 80 cm.

Solution:

Top books for IIT JEE

Hi friends,

One of the major component of Competitive exams like IIT JEE is the numerical portion rather than theory. Thus it becomes essential that one should practice enough number of numericals and enough variety of numericals. Keeping this in mind I am going to suggest the following books for IIT JEE preparation subject wise. Some of these books are:

   1. Physics

HC Verma: It is a very good book for preparing for IIT JEE. One can read theory, read solved examples and practice back questions. It is a MUST for serious JEE preparation.

NCERT Physics: It is an excellent book for theory and practice of all questions is a must. Most of the students are of the impression that if I am preparing for JEE then I would definitely be able to solve NCERT questions. Remember practicing a good number of questions is necessary but the variety of questions is also a must. Don't be over confident. Do take NCERT books seriously for BOARD as well as JEE preparation.

Pradeep Objective: Objective is the first thing that comes to mind when one thinks about Pradeep. All competitive exams are objective based these days, thus it becomes necessary to practice a lot of objective questions ( A lot means a lot !). Pradeep is the best to solve this problem and perform timed practice tests. By timed practice tests I mean that you select 100 questions for a topic and put a watch in front you and time that in 100 minutes how many of them were you able to solve. this helps you monitor and increase your speed.

Apart from this be regular with your school and tuition assignments. 

  2. Chemistry

Chemistry consists of three portions, namely Organic, Physical and Inorganic. Out of the three Organic and Physical are major and Inorganic is basically ratta based ( Pardon me for those whose favourite subject is Inorganic chemistry, but I am talking of most of the students and weightage in JEE exam wise). I will be specifying which book is good for which topic below:

NCERT Chemistry: A very good book for theory and practicing questions for all three.

Pradeep: A very good book for theory and theory based questions for all three.

P. Bahadur: A MUST for Physical chemistry. You cannot afford to miss it for physical chemistry. If one has done this book whole heatedly, then one can rest assured that Physical Chemistry is done!

Learn your organic chemistry reactions and learn to play with them. 
As for inorganic chemistry I too am still confused. If someone finds how to prepare for this. Please Please Please.... write in comments below. I shall be very grateful.

  3. Mathematics:

NCERT Mathematics: A must read for all.

ML Khanna/ A Das Gupta: One of these is a must for Maths. If you can practice both you are a genius. But for normal ones, read both initially and whichever style suits you follow that one.

Arihant: A very good book to practice tough questions. If you can find time to do this, it will be very good.

RD Sharma Objective: A good book for practicing objective questions and test papers which is a must for increasing speed.


So fooooooffffff.... that was all with books. To study these Time Management is a must.

I will write another article on Time Management for you all.

Guys I need your support. I have so much to share with you all but I will be encouraged to write more only if I get views on my blog which in turn happens only when you guys read, share, comment, subscribe and follow my blog.

Gravitation

Question:

Near to the point where I am standing on the surface of Planet X, the gravitational force on a mass m is vertically down but has magnitude myy2 where y is a constant and y is the mass's height above the horizontal ground. (a) Find the work done by gravity on a mass m moving from r1 to r2, and use your answer to show that gravity on Planet X, although most unusual, is still conservative. Find the corresponding potential energy. (b) Still on the same planet, I thread a bead on a curved, frictionless, rigid wire, which extends from ground level to a height h above the ground. Show clearly in a picture the forces on the bead when it is somewhere on the wire. (Just name the forces so it's clear what they are; don't worry about their magnitude.) Which of the forces are conservative and which are not? (c) If I release the bead from rest at a height h, how fast will it be going when it reaches the ground?

Solution:

Mechanics

Question:

The tool shown is used for straightening twisted members as wooden framing is completed. If the force P = 30 lb is applied to the handle as shown, determine the normal forces applied to the in- stalled stud at points A and B. Ignore friction.

Solution:

Fluid Mechanics

Question:

What force must be exerted through the bolts to hold the dome in place? The metal dome and pipe weigh 6 kN. The dome has no bottom. Here ℓ = 80 cm.

Solution:

Can of Pet Food

Question: 

A can of pet food has the following internal dimensions: 102 mm height and 73 mm diameter (each ± 1 mm at odds of 20 to 1). The label lists the mass of the contents as 397 g. Evaluate the magnitude and estimated uncertainty of the density of the pet food if the mass value is accurate to ± 1 g at the same odds.

Solution:

Bead and rod

Question: 

A bead of mass m slides without friction on a rod that is made to rotate at a constant angular speed ω. Neglect gravity. (a) Show that r = r0e^ωt is a possible motion of the bead, where r0 is the initial distance of the bead from the pivot. (b) For the motion described in part (a), find the force exerted on the bead by the rod. (c) For the motion described above, find the power exerted by the agency that is turning the rod and show by direct calculation that this power equals the rate of change of kinetic energy of the bead.

Solution: 

Sample Physics Question

Hi all,
Pretty excited as it is my first post. We'll here's a random question which one of the students asked me. Enjoy reading !!

Question: Determine whether the block shown is in equilibrium and find the magnitude and direction of                          the friction force when θ=  25° and P = 150 lb