Question

11.
A block of mass m is being pulled along rough
horizontal surface. Coefficient of friction between
the block and the surface is u. If another block of
mass m/2 is placed on the block, what is coeffi-
cient of friction between block and surface?
(1) 3u/2
(2) 5u/2
(3) u/2
(4)u
(here "u" is new)
​

Answer 1

Answer:

(2)5u/2

Explanation: