## Visualisation paradox of tension

My son and I were discussing tension in a handheld rope with a 10 lbm weight on the end. The hand exerts an upward force of 10 lbf and gravity exerts a 10 lbf downward (net = zero). With these vector forces acting in opposite directions they would appear to ADD to 20 lbf of tension in the rope rather than 10 lbf. Where is the conceptual fallacy? How can I explain this clearly? Asked Hecket Answer When you consider the two points where force vectors are drawn 1. At hand and 2. On the hanging weight Tension of 10 lbf is produced throughout the rope. See the diagram

## Physics – Centre of Mass Problem

The linear mass of density of a ladder of length l increases uniformly from one end A to the other end B.(a) Form an expression for the linear mass density as a function of distance x from end A where linear mass density d. The density at one end being twice that of the other end.(b) Find the position of the centre of mass from end A.

Asked Chandravardhan

## QUESTION FROM ELECTRIC CIRCUIT

Sir, I am sending the circuit diagram in which I am having doubt. Kindly clarify the questions.

Asked Rajareddy

## Tips for Scoring High Marks in Class 12th Physics CBSE Exam

Among all the exams, CBSE class 12th Board Exam is the most important exam in every student’s life because it decides a student’s future career. Even most of the colleges and universities have a very strict cut-off for the shortlisting of students for various courses. A structured syllabus for each concerned subject is always essential to achieve good marks in any kind of examination.

Physics is the most important and one of the tough subjects in CBSE. Talking about physics, it requires logical solving abilities and conceptual understanding. For better knowledge about every chapter, one has to be thorough with the basics. As physics includes many difficult and complicated topics, students find this subject really difficult to understand. But these problems can be easily overcome with a structured syllabus, a good understanding about the important topics and a planned preparation strategy.

**Important physics topics one should cover:**

There are a number of topics in the CBSE class 12th physics syllabus but in order to score well in the physics exam students should cover all the important topics. So, let’s check out the list of important topics given below,

- Communication Systems
- Electrostatics
- Electronic Devices
- Dual nature of matter
- Magnetism
- Optics
- Atoms and Nuclei

**Tips for Scoring High Marks in Class 12th Physics CBSE Exam:**

** **

**Practice Graphs On a Regular Basis:**Graphs are really helpful in learning complex concepts fast. Learning with graphs and images allows us to retain concepts in our minds for a longer period of time.**Learn all Formulas Rigorously:**Try to note down all the formulas present in the physics syllabus at one place. So that you can access them on the go. Formulas are very important and should be practiced well as physics includes more problematic questions compared to theoretical questions.**Solve Last Year Questions:**The preparation for the exam is valueless without practicing questions on your own. Students should solve as many questions as they can from various books and websites. For a strong grip on the subject, students must solve last 10 year cbse question papers rigorously. It also helps to understand the question pattern and the mark distribution for variety of questions. Sometimes short type questions (i.e. 1 mark and 2 mark questions) come directly from previous year question papers. So memorizing these 1 mark questions might help you in scoring well in short type question section.**Physics is not restricted to Numerical:**Students usually misunderstand that physics is more about numerical. It is true to some extent as most of the chapters cover numerical problems but students should not ignore the theoretical portion in physics. Because only 15 marks of numerical will be asked in the CBSE class 12 board exams. It is advised not to waste time in solving numerical. If you find difficulty in this section then proceed ahead and attend other sections.

For more tips and tricks to score high marks in physics and other subjects, subscribe to our Byju’s YouTube Channel.

## Acceleration and Vectors

## Scenario

Person walks up the step and most of his body weight is distributed on back leg and little weight placed on front leg. The normal vector for the back leg is greater than the front leg.

Does this mean that the friction vector for the back leg will be greater than the front leg’s friction vector?

The sum of two normal vectors is greater than the weight vector.

Is the person speeding up, slowing down, or moving in constant speed in horizontal direction?

What about vertical? Is person slowing down, speeding up or moving at a constant speed?

Asked by Kora

## Think IIT? Think HCV

You can Buy Concepts of Physics by HC Verma online from these links

Concepts of Physics (Volume – 1) 1st Edition

Concepts of Physics 2 1st Edition

## Nobel Prize in Physics 2017 goes to Rainer Weiss, Barry C. Barish and Kip S. Thorne

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics 2017 with one half to

**Rainer Weiss **

LIGO/VIRGO Collaboration

and the other half jointly to

**Barry C. Barish **

LIGO/VIRGO Collaboration

and

**Kip S. Thorne**

LIGO/VIRGO Collaboration

*“for decisive contributions to the LIGO detector and the observation of gravitational waves”*

Read more at

https://www.nobelprize.org/nobel_prizes/physics/laureates/2017/press.html

https://www.nobelprize.org/nobel_prizes/physics/laureates/2017/popular-physicsprize2017.pdf

https://www.nobelprize.org/nobel_prizes/physics/laureates/2017/advanced-physicsprize2017.pdf