CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

Two masses 8 kg and 12 kg are connected at the two ends of a light inextensible string that goes over a frictionless pulley. Find the  acceleration of the masses, and the tension in the string when the masses are released.
 



    Solution

    The correct option is

    The given system of two masses and a pulley can be represented as shown in the following figure:

    Smaller mass, m1=8 kg
    Larger mass, m2=12 kg
    Tension in the string = T
    Mass m2, owing to its weight, moves downward with acceleration a, and mass m1 moves
    upward.
    Applying Newton's second law of motion to the system of each mass:
    For mass m1: The equation of motion can be written as:
    Tm1g=m1a ..........(i)
    For mass m2: The equation of motion can be written as:
    m2gT=m2a ........(ii)
    Adding equations (i) and (ii), we get:
    (m2m1)g=(m1+m2)a a=(m2m1m1+m2)g(iii)=(12812+8)×10=420×10=2 m/s2
    Therefore, the acceleration of the masses is 2 m/s2.
    Substituting the value of a in equation (ii), we get:
    m2gT=m2(m2m1m1+m2)g12×10T=12×2T=96 N
    Therefore, the tension in the string is 96 N


    Physics
    NCERT Textbook
    Standard XI

    Suggest Corrections
    thumbs-up
     
    0


    similar_icon
    Similar questions
    View More


    similar_icon
    Same exercise questions
    View More


    similar_icon
    People also searched for
    View More



    footer-image