Question

Masses of block A, B and C are 10 kg, 2kg and 3kg respectively and they are arranged as shown in the figure. There is a uniform electric field towards right of magnitude 10 N/C and block C has charge 0.5 C. If frictional coefficient between block A and the floor is 0.1, between block C and wall is 0.2 and there is no friction between A and B, then which of the following option(s) is/are correct: (Assuming pulley and string to be ideal)

• A. Acceleration of block B is 1.285 $m/s^2$.
• B. Acceleration of block C is 2.14 $m/s^2$.
• C. Acceleration of block A is 0.855 $m/s^2$.
• D. Tension in the string is 22.57 N.

Answer 1

Answer: (B), (C), (D)

The correct options are
B Acceleration of block C is 2.14 $m/s^2$.
C Acceleration of block A is 0.855 $m/s^2$.
D Tension in the string is 22.57 N.

(B, C, D)

For C-block
29-N = 3a ….(i)

For B-block
20-T = 2b …(ii)

For system of A and B
T-0.1(100+T)=12(a+b) $\cdots$ (iii)
By solving (i), (ii) and (iii), we get
T=22.5N; a= 2.14 $m/s^2$
B = -1.285 $m/s^2$