A block B is placed on block A. The mass of b | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) If the applied force $F$ is less than the limiting friction $f_l$ between block $A$ and $B$,both blocks move together with a common acceleration.$

Vedclass · Accepted Answer

Vedclass · Answer

(D) If the applied force $F$ is less than the limiting friction $f_l$ between block $A$ and $B$,both blocks move together with a common acceleration.$a_A = a_B = \frac{F}{m_A + m_B}$Since $F$ increases linearly with time,the common acceleration also increases linearly with time.When the applied force $F$ exceeds the limiting friction $f_l$,the blocks begin to slip relative to each other.For block $B$,the net force is $F - f_k$,where $f_k$ is the kinetic friction. Thus,the acceleration of $B$ is $a_B = \frac{F - f_k}{m_B}$. Since $F$ continues to increase,$a_B$ increases with a steeper slope than before.For block $A$,the only horizontal force acting on it is the kinetic friction $f_k$ exerted by block $B$. Thus,the acceleration of $A$ is $a_A = \frac{f_k}{m_A}$. Since $f_k$ is constant,$a_A$ becomes constant after slipping begins.Comparing the slopes and behavior,graph $D$ correctly represents this: both accelerations increase together until slipping occurs,after which $a_B$ continues to increase while $a_A$ remains constant.

Similar Questions

$A$ balloon with mass $m$ is descending down with an acceleration $a$ (where $a < g$). How much mass should be removed from it so that it starts moving up with an acceleration $a$?

$A$ $\sqrt{34}\,m$ long ladder weighing $10\,kg$ leans on a frictionless wall. Its feet rest on the floor $3\,m$ away from the wall as shown in the figure. If $F_{f}$ and $F_{w}$ are the reaction forces of the floor and the wall,then the ratio of $F_{w}/F_{f}$ will be:
(Use $g=10\,m/s^{2}$)

$A$ horizontal force $F = mg/3$ is applied on the upper surface of a uniform cube of mass $m$ and side $a$,which is resting on a rough horizontal surface having $\mu_S = 1/2$. The distance between the lines of action of $mg$ and the normal reaction $N$ is:

Vedclass Test Series

Exam Paper Generator

Online Exam Module