## Kumar Ketan is teaching live on Unacademy Plus

Kumar Ketan Follow 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. 283 Views in last 30 days 1,178 Lifetime Views 5 Courses 460 Followers Following Course Overview Course Overview Expected topics of General Awareness for UPSC CSE SSC / Railway with some details Expected topics of General Science for Railway Group C & D with some details For which diode is used a) Modulation b) Oscillation c) Amplification d) purification VOTE enroll VOTE enroll By Kumar Ketan By Kumar Ketan By Kumar Ketan (Hindi) General Awareness: Most Important 50 Question for... (Hindi) Most Important 100 General Science Questions: Railway... (Hindi) Previous Years Questions asked in UPPSC/SSC 6 Lessons 8 Lessons 25 Lessons https://unacademy.com/user/KumarKetan

ELASTIC COLLISION IN TWO DIMENSIONS In general, the collision are two dimensional, where the initial velocities and the final velocities may lie in a plane. So, when two bodies travelling initially along the same straight line collide without loss of kinetic energy and move along different directions in a plane after collision, the collision is said to be elastic collision in two dimensions

Before the collision mm2 After the collision uy sin 01/ cos 02/ cos

i initial i final Ki initial = final Knowns : m,m , , vi, Unknowns 121i

PROBLEMS OF COLLISIONS: Cart A (50. kg) approaches cart B (100. kg initially at rest) with an initial velocity of 30. m/s. After the collision, cart A locks together with cart B. both travels with what velocity? . Before collision after collision mA 50 kg, vA 30. m/s (50.kg)(30.m/s) + (100.kg)(0) (50.kg +100.kg)v = v 10. m/s mass increases by 3 times (50 kg to 150 kg), speed decrease by 3 times (30 m/s to 1O m/s)

A block of mass M initially at rest on a frictionless horizontal surface is struck by a bullet of mass m moving with horizontal velocity v. What is the velocity of the bullet-block system after the bullet embeds itself in the block? Before collision mv M(O) mv O after collision (m M)v mM)v' mv / (M+m)v'