21
tapanmast Vora
·2009-03-25 09:19:32
Kalyan : how did u get f = 10a?
21
tapanmast Vora
·2009-03-25 10:56:31
YEAH!!!!!!!!!! k k...... Finally I got it!!!! [132]
THANKS A LOT subhash n Kalyan!!! [1]
1
Kalyan Pilla
·2009-03-25 10:46:03

What you drew is correct Xcept that it is 30a and not (30+10)a
11
Subash
·2009-03-25 10:44:53
from your diag(considering m and M for boy and cart)
120-Fr=ma(eqn for boy)
Fr=ma( eqn for cart)
(a is same for both to avoid sliding)
Normal reaction between the two bodies N=mg
so Fr≤μN
take equality for minimum
applying values you can get the ans
21
tapanmast Vora
·2009-03-25 10:32:18
Now pl. help or point da error

11
Subash
·2009-03-25 09:42:47
@tapan
f=10a in kalyan's eqation
is force equation of the cart
1
Kalyan Pilla
·2009-03-25 09:42:17
the reaction of friction is responsible only for the acceleration of the cart.
And the cart weighs 10 kg[1]
11
Subash
·2009-03-25 09:35:48
just change that tapan you will get the answer
11
Subash
·2009-03-25 09:35:05
Nishant bhaiya
N=mg
it is between the two bodies not the entire thing!
21
tapanmast Vora
·2009-03-25 08:46:55
oh k...
so
N = 40g, a =120/(M+m) = 3, M = 30, m =10;
but then F = 90 = μ(400)
then μ≠0.1 [2]
62
Lokesh Verma
·2009-03-25 08:39:43
120-F=ma
F=Ma
F≤μN
N=(M+m)g
now solve?
21
tapanmast Vora
·2009-03-25 07:52:30
Ok...
So 120N = 40a
a = 3
Friction = μN
N = 30g
we gotta equate Friction to ?? ma kya??
11
Subash
·2009-03-25 07:40:06
they travel with same acceleration
simple fbds give the answer