Hello Everyone. WE come across many tough problems in brilliant and if we are not able to solve it, we will surely be curious to know the solution. But few of the problems remain unanswered. In such case i think there should be feature to request for a solution to the problem. In physics i came across THIS Problem , I couldn't do it. so i waited for people to write a solution so that i can learn how to solve it. But no one came up with one. So, if there is a feature as mentioned above, it will inform those who have solved it that someone needs a solution. It will be very helpful. SO, what do you think? And if possible could anyone write solution to the above problem.