A system consists of two cubes of mass `m_(1)`, and `m_(2)` respectively connected by a spring of force constant k. force (F) that should be applied to the upper cube for which the lower one just lifts after the force is removed, is A. mgB. `m_(2)g`C. `(m_(1)+m_(2))g`D. `(m_(1)m_(2))/(m_(1)+m_(2))g`

A system consists of two cubes of mass `m_(1)`, and `m_(2)` respective

1.	A system consists of two cubes of mass `m_(1)`, and `m_(2)` respectively connected by a spring of force constant k. force (F) that should be applied to the upper cube for which the lower one just lifts after the force is removed, is A. mgB. `m_(2)g`C. `(m_(1)+m_(2))g`D. `(m_(1)m_(2))/(m_(1)+m_(2))g`
Answer» Correct Answer - C Let `x_(0)` be the maximum compression, then `m_(1)g+F=kx_(0)" "...(i)` `"and "(1)/(2)kx_(0)^(2)=m_(1)gx_(0)" "...(ii)` If x is the maximum elongation, then `kx = m_(2)g" "...(iii)` `"and "-(1)/(2)kx^(2)=m_(1)g(x+x_(0))" "...(iv)` `"or "k(x_(0)-x)=2m_(1)g` From Eqs. (i) and (iii), we get `m_(1) g+ F- m_(2)g = k (x_(0) -x) =2m_(1)g` `"or "F = 2m_(1)g + m_(2) g-m_(1)g=(m_(1)+m_(2))g`

Discussion

No Comment Found

Related InterviewSolutions

Starting from rest, the time taken by a body sliding down on a rough inclined plane at `45^(@)` with the horizontal is twice the time taken to travel on a smooth plane of same inclination and same distance. Then, the coefficient of kinetic friction isA. 0.25B. 0.33C. 0.5D. 0.75
The vertical displacement of a block A in meter is given by `y=t^(2)//4` where t is in second. The downward acceleration `a_(B)` of a block B ( in `m//s^(2)`) is A. 4B. 8C. 10D. 5
Consider the following statement. When jumping from some height, you should bend your knees as you come to rest instead of keeping your legs stiff. Which of the following relations can be useful in explaining the statement?A. `Deltap_(1)=-Deltap_(2)`B. `DeltaE = -Delta(PE+KE)=0`C. `FDeltat=mDeltav`D. `Deltax prop DeltaF`
Pseudo force isA. electromagnetic in natureB. a nuclear forceC. a gravitational forceD. None of the above
A weight w is to be moved from the bottom to the top of an inclined plane of inclination `theta` to the horizontal. If a smaller force is to be applied to drag it along the plane in comparison to lift it vertically up, the coefficient of friction should be such that.A. `mugt tan((pi)/2-(theta)/2)`B. `mult tan((pi)/2-(theta)/2)`C. `mu lt tan theta`D. `mugt tan. (pi)/(4)`
A man is standing on a sparing platform, Reading of spring balaance is `60kg` wt If man jumps outside the platform then the reading of the spring balance .A. Becomes `gt60 kg` wt initially and then decrease to zeroB. Becomes `llt60 kg` wt first and then decreases to zeroC. Becomes =60 kg wt fist and then decrease to zeroD. Remains decreasing till zero
A smooth block is released at rest on a `45^(@)` incline and then slides a distance `d`. The time taken to slide is n times as much to slide on rough incline than on a smooth incline. The coefficient of friction isA. `mu_(s)=1-1/(n^(2))`B. `mu_(s)=sqrt(1-1/(n^(2)))`C. `mu_(k)=1-1/(n^(2))`D. `mu_(k)=sqrt(1-1/(n^(2)))`
A man is pulling a rope attached to a block on a smooth horizontal table. The tension in the rope will be the same at all pointsA. if and only if the rope is not acceleratedB. if and only if the rope is masslessC. if either the rope is not accelerated or is masslessD. always
In figure, block A is released from rest, when spring is at its natural unstretched length. For block B of mass M to leave contact with the ground at some stage, the minimum mass of A must be A. 3MB. `(M)/(2)`C. MD. cannot say
A block weighing w is held against a vertical wall be pressing horizontally with a force F. Then, F needed to hold the block is A. equal to wB. equal to `(w)/(mu)` onlyC. greater than `(w)/(mu)` onlyD. greater than or equal to `(w)/(mu)`

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment