Guest

a ball with mass m strikes a rough vertical wall with an angle of 37 degress ( along the common normal)and rebounds with the same angle. Find the coefficient of friction

a ball with mass m strikes a rough vertical wall with an angle of 37 degress ( along the common normal)and rebounds with the same angle. Find the coefficient of friction

Grade:12th Pass

2 Answers

arnab adhikary
16 Points
11 years ago

0.25

Arpit Jaiswal
31 Points
11 years ago

I guess u meant coefficient of restitution, by coefficient of friction!!

First we should know that coefficient of restitution, e= relative speed of seperation  = RSS/RSA

         relative speed of approach

(Wish i could help you with the visuals but i don''t know how to)

Never mind, lets continue this way..

before collision

let the ball fall at angle of 37degree, with the normal, then dividing the velocity into components we have-

vsin37 along verticall downward, direction is -j^, and

vcos37  along horizontal towards the wall, i.e direction along -i^

 

after collision

let the velocity be u, alog vertically downward it is     usin37 -j^

and along horizontal it is ucos37 +i^

 

Now vertical velocity is not affect during collision, because only horizontal velocity takes part in collision.

therefore, usin37=vsin37

or, u=v

therefore horizontal velocity after collision is,      vcos37

applying very first formulae, we have e= RSS/RSA 

or, e=vcos37/vco37=1

therefore, we can say collision is perfectly elastic.

 

 

Now we have a shortcut also, when we have angles of collision and refelection, that might help (:D)-

e=tanΘ1/tanΘ2

here tanΘ1 is intial angle and tanΘ2 isfinal angle..

hope this helps :D

AJ

(Hope you liked this, if  yes then please vote this answer ;))

 

Think You Can Provide A Better Answer ?

ASK QUESTION

Get your questions answered by the expert for free