AP EAMCET201726 Apr 2017Morning ShiftPhysicsLaws of MotionActual
Two blocks of masses ' M ' and ' m ' are placed on one another on a smooth horizontal surface as shown in the figure. The force ' F ' is acting on the mass ' M ' horizontally during time interval ' t '. Assuming no relative sliding between the blocks, the work done by friction on the blocks is .......... .
Options
- AF t 2(M+m)
- BM+m m t^2
- Cm F^2 t^2 2(M+m)^2
- DF^2 t^2 (M+m)
Correct answer
C. m F^2 t^2 2(M+m)^2
Step-by-step solution
From (i) & (ii), we get a= F m+M and f= m F m+M Distances moved in time t(s) = 1 2 a t^2= 1 2 ( F M+m ) t^2 Work done by friction =f s = ( m F M+m ) 1 2 F t^2 (M+m) = m F^2 t^2 2(M+m)^2