## Kumar Ketan is teaching live on Unacademy Plus

0 minutes today Home ExploresSearch Courses, Topics&Educators Kumar Ketan Edit Profile Hey, this is kumar Ketan. I'm graduate in physics and doing further studies. I would love to teach you and give you all my knowledge. 415 Views in last 30 days 1,377 Lifetime Views 7 Courses499 Follwers Following Expected topics of Current Affairs for SSC/IBPS/UPSC/PCS/UPPSC/ALL OTHER GOVERNMENT EXAMS with some details COLLISION Course Overview A col ision as an isolated event in which two or more colliding bodies exert relatively strong forces on each other for a relatively short time CURRENT AFFAIRS Expected topics of General Awareness for UPSC CSE/SSC/ Railway with some details 5 Collision between particles have been divided broadly into two typer: 1. Elastk collision 1st VOTE enroll By Kumar Ketan By Kumar Ketan By Kumar Ketan (Hindi) Collision for IIT JEE (Hindi) Current Affairs 2018 for UPSC CSE (Hindi) General Awareness: Most Important 50 Question for. https://unacademy.com/user/KumarKetan

A ball collides elastically with another ball of the same mass. The collision is oblique and initially one of the ball was at rest. After the collision the two balls move with same speeds. What will be the angle between the velocity of the ball after the collision? (a) 30 (b) 45 (c) 60 (d) 90

vsin 01 U cos 2 M M02 coS O01 v sin 2

Before collision- let velocity of first ball is velocity of second ball is u2 According to question, u2 -0 After collision, velocity of both ball is v

From conservative of linear momentum where, u =0 01- And Therefore, say,which gives

From equation (1) COS COS 72 u-2v cos 0 from conservation of energy 2 2 2 here ui- u

2 2 0 2 therefore 2v 2v 2 2 cos 45

which gives = Vi= ,-45 and 1 + 2 = 90

Statement-1: The centre of mass and centre of gravity of a body are two different positions in general. Statement-2: The centre of mass and centre of gravity of a body coincide if gravitational field is uniformm (a)Statement-1 is True, Statement-2 is True; Statement-2 is 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.