Question

5.
A block of mass m is in contact with the cart C as
shown in the figure. The coefficient of static friction
between the block and the cart is u. The acceleration
a of the cart that will prevent the block from falling
statisfies :-
C
m
mg
(1) a < 3
(2) a >
u
u
g
g
(3) a >
um
(4) a 2​

Answer 1

Answer:

The expression for the molality is

(1−X

A

)m

B

X

A

×1000

=m.

For two different mole fractions of A, i.e. 1/2 and 1/3, the expression becomes,

(1−(

2

1

))m

B

2

1

×1000

=m

1

......(1)

(1−(

3

1

))m

B

(

3

1

)×1000

=m

2

......(2)

Divide equation (2) with equation (1).

(1−(

2

1

))m

B

2

1

×1000

(1−(

3

1

))m

B

(

3

1

)×1000

=

m

1

m

2

Hence,

m

1

m

2

=

2

1

.