# No one can solve this!!

In the arrangement shown in the figure,find the acceleration of M.The pulleys and strings are light!

## 11 Answers

1
dimensions (dimentime) ·

i think i got the ans

acc of M = (M-5m)g/(M+15m)...........

1
dimensions (dimentime) ·

let acceleration M be a & of m be b

see, by equation of constraint u will get

b = 3a

by newtons motion

Mg-2.5T = Ma

2.5T-5mg = mb

where T is tension in rope connecting roof & M

solve & u will get the ans,

one more thing
can u tell me how to use latex in this forum..............

341
Hari Shankar ·

Are you sure its not g(M-5m)/(M+25m)?

Thats the answer I get.

Logically the minus sign has to be there.

1
greatvishal swami ·

i m getin same as dimen but prophet frm where dat M+25m come isnt it M+15m

341
Hari Shankar ·

If the acceleration of M is a, what is the acceleration of m?

You seem to have taken it as 3a. Its 5a.

1
greatvishal swami ·

********edited
its 5a ......correction
& -ve sign has to be there

3
msp ·

great vishal please post me the soln with your constraint relations

3
msp ·

hey dimensions I think u have went wrong with your equations

3
msp ·

yes the acceleration of m is 5 times that of the acc of M
the eqns are

Mg-(T1+T)=Ma
T-mg=m3a
where T=T1/4

1
skygirl ·

yes the ans given is correct only..

the constraint eqn is : 5A + a=0 (A= acc of M, a= acc of m)

the force eqns are:

5T-Mg = - MA --- 1

T-mg= -ma ----2

I) now find a and A in terms of T.

II) put in the constarint eq. ... so u will get T.

III) then find a and A from the force equations.. :)

1
aaru s ·

5T-Mg=Ma-----------1
mg-T = 5ma---------2

multiplying eqn 2 wid 5 and thn adding them....we get....5mg- Mg=Ma +25 ma

a=g(5m-M)/M+25m