JEE Main & Advanced Physics NLM, Friction, Circular Motion Question Bank Mock Test - Newtons Laws of Motion without Friction

  • question_answer
    A block of mass \[m\]is placed on a smooth wedge of inclination \[\theta \]. The whole system is accelerated horizontally .so that the block does not slip on the wedge. The force exerted by the wedge on the block (g is acceleration due to gravity) will be

    A)  \[mg\,\cos \,\theta \]                  

    B)  \[mg\,\sin \,\theta \]

    C)  \[mg\]                          

    D)  \[mg/\,\cos \,\theta \]

    Correct Answer: D

    Solution :

    [d] When the whole system is accelerated towards left, then pseudo force (ma) works on a block towards right. For the condition of equilibrium: \[mg\sin \theta =ma\cos \theta \] \[\Rightarrow a=\frac{g\sin \theta }{\cos \theta }\] Therefore, force exerted by the wedge on the block \[N=mg\cos \theta +ma\sin \theta \] \[=mg\cos \theta +m\left( \frac{g\sin \theta }{\cos \theta } \right)\sin \theta \] \[=\frac{mg(co{{s}^{2}}\theta +si{{n}^{2}}\theta )}{\cos \theta }=\frac{mg}{\cos \theta }\]


You need to login to perform this action.
You will be redirected in 3 sec spinner