Grade 12th passMechanics

if accleration of A is [a] then what will be the accleration of B 2a .......... or ....... [2+ cos@]a
which one is correct and why

answer is 2a by displacement method and [ 2+cos@]a by tension method but which one
is correct

Question image for if accleration of A is [a] then what will be the a

Gayatri Jayesh Bondriya

11 Years agoGrade 12th pass

7 Answers

Nicho priyatham

11 Years ago

u might have done some mistake

both the methods should give any1

each 1 cannot give its own answer

check trail and error

if teta=0 u get ab=3a

if aa=90 u get ab=2a

so the ans must be (2+cos(teta))a

PLZ APPROVR IF USEFUL
n in case of any doubts ask in ans box

Gayatri Jayesh Bondriya

11 Years ago

but answer is 2a by displacement method given in BM. SHARMA

AND U ALSO OBSERVE THAT IF WEDGE MOVES IN RIGHT BY DISPLACEMENT x THE ROPE WILL BE DISPLACED BY 2x AND IN SAME TIME IF BLOCK MOVES DOWN WITH y THEN IN THAT CASE y=2x ON DOFFRENCIATION aB =2a

Gayatri Jayesh Bondriya

11 Years ago

not doffrenciation it is diffrenciation

on double diffrenciation it will be accleration

Nicho priyatham

11 Years ago

it the wedge moves by right by X then the block moves by 2X

this is ACCERLATION OF B W.R.T A

not wrt GROND

but u have to find wrt ground

Gayatri Jayesh Bondriya

11 Years ago

sir means [ 2+cos@] a is the accleration wrt ground

Nicho priyatham

11 Years ago

yes i dont have new edtion of bm sharma but having 2012 edition in my edtion their is a similar kind of problem in concept application (excs 7.3) there is a similar kind of problem their

here he gave solution clearly by using vector method

i dont think the ans is 2+cos@

so can u plz check it 1s