Block A of mass m and block B of mass 2m are placed on a fixed triangular wedge by means of a light and inextensible string …

Q: Block A of mass m and block B of mass 2m are placed on a fixed triangular wedge by means of a light and inextensible string and a frictionless pulley as shown in figure. The wedge is inclined at 45° to the horizontal on both sides. The coefficient of friction between the block A and the wedge is 2/3 and that between the block B and the wedge is 1/3. If the system of A and B is released from rest, then the acceleration of A is

Numerical

(a) 1.5 ms-2

(b) 0

(c) 0.5 ms-2

(d) 1 ms-2

Ans: (b)

(fmax)A = μA(m g cos45)

(fmax)B = μB(2m g cos45)

Hence , the maximum value of friction obtained is

fmax = (fmax)A + (fmax)B …(i)

Net pulling force on the system is

F = F1-F2

F = 2m g sin45 – mg sin45 …(ii)

Pulling force < fmax

Therefore, the system will not move or the acceleration of block A will be zero.

Two blocks A and B each of mass 1 kg are on an inclined plane of inclination 37°. The coefficient of kinetic friction …..

Q: Two blocks A and B each of mass 1 kg are on an inclined plane of inclination 37°. The coefficient of kinetic friction between blocks and the inclined plane is µk = 0.5. At t = 0, block A is released from rest but block B is projected up along inclined plane with speed 10 m/s. The initial separation between blocks is 6 m. Find the distance from initial position of A, where they will collide.

Numerical

(a) 1 m

(b) 2 m

(c) 3 m

(d) 4 m

Ans: (a)