## 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 1Following Course Overview Course Overview Expected topics of General Awareness for UPSC CSE/SSC/for Railway Group C & D with some Railway with some details . For which diode is used a) Modulation b) Oscillation c) Amplification d) purification Expected topics of General Science details 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

unacademy $Coefficient of restitution or coefficient of resilience *Numerical with Trick

Coefficient of restitution or coefficient of esilience In actual practice, collision between all real objects are neither perfectly elastic nor they are perfectly inelastic. They are called imperfect or semi elastic collision. The degree of elasticity of a collision is determined by a quantity, called coefficient of restitution or coefficient of resilience Coefficient of restitution or coefficient of resilience of a collision is a defined as the ratio of relative velocity of separation after collision to the relative velocity of approach before collision It is represented by e

relative velocity of separation (after collision) e relative velocity of approach (before collision) 7 2 7 ITI 2 U1 ITi mm2 my m 2

Tricks for numericals: If we find final velocity after "n" bounce then use equation-

Form a height of 81 meter a ball is dropped. f e-1/3 what is the speed of the ball after 2 collision with the ground.? Solution: V2 = 0 + 2 10 81 v- 18V5 1 3

Trick for numericals: If we find final height after n bounce then we use: 2n

From a height of 100 meter a boll of mass 2 kg is dropped if e=1N2 then calculate its final height? Where no of bounce is 2 Solution: 2 2 100 V2 4. = ! ) 100 V2 1 H =- 100 4 H 25 m