Home
Class 11
PHYSICS
Two children A and B of same mass (inclu...

Two children `A` and `B` of same mass (including their caps) `M` are sitting On a see-saw as shown in Fig. Initially, the beam is horizontal. At once, child `B` throws away his cap (mass `M/25`) which falls at point `Q`, midpoint of the left half of the beam, due to this the balance of beam is disturbed. To balance it again what is the mass in required to be put at point `P` on the right half of the beam?

Text Solution

Verified by Experts

Initially, the beam was horizontal because the centre of mass of the system was at the centre (pivot of see saw) of the system. When child `B` threw his cap to point `Q`, centre of mass of the system shifted to the left of the pivot and that's why the balance got disturbed and beam started rotting in anticlock sense. To balance it again we must put some mass to the right of it so as to displace the centre of mass of the system again at the centre of the system.
If a mass `m` is put at point `P`, bring the centre of mass of the system at the cente, we have
`ML/2+M/25L/4=(24ML)/25 L/2+mL/4`
or `m=0.2 M`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • CENTRE OF MASS

    CENGAGE PHYSICS|Exercise Exercise 1.2|23 Videos
  • CENTRE OF MASS

    CENGAGE PHYSICS|Exercise Exercise 1.3|24 Videos
  • CENTRE OF MASS

    CENGAGE PHYSICS|Exercise Solved Examples|13 Videos
  • CALORIMETRY

    CENGAGE PHYSICS|Exercise Solved Example|13 Videos
  • DIMENSIONS & MEASUREMENT

    CENGAGE PHYSICS|Exercise Integer|2 Videos

Similar Questions

Explore conceptually related problems

A faulty balance with unequal arms has its beam horizontal. Are the weights of the two pans equal ?

The radius of plant A is half the radius of planet B . If the mass of A is M_(A) , what must be the mass of B so that the value of g on B is half of its value on A ?

Knowledge Check

  • A proton beam is fired from west to east and an electron beam is fired parallel to it in the same direction. Force on the electron beam will be

    A
    upwards
    B
    downwards
    C
    towards the proton beam
    D
    away from the proton beam
  • When slightly different weights are placed on the two pans of a beam balance, the beam comes to rest at an angle with the horizontal. The beam is supported at a single point P by a pivot.

    A
    The net torque about P due to the two weights is nonzero at the equilibrium position .
    B
    The whole system does not continue to rotate about P because it has a large moment of inertia.
    C
    The centre of mass of the system lies below P .
    D
    The centre of mass of the system lies above P.
  • A rigid massless beam is balanced by a particle of mass 4m in left hand side and a pulley particle system in right hand side. The value of x/y is

    A
    `7/6`
    B
    `5/6`
    C
    `1:1`
    D
    `11//12`
  • Similar Questions

    Explore conceptually related problems

    The radius of planet A is half the radiius of planet B. If the mass of A is M_(A) , what must be the mass of B so that the value of g on B is half that of its value of A ?

    The radius of the planet A is half the radius of planet B. If the mass of A is M_(A) What must be the mass of B so that the alueof g on B is half that of its value on A?

    If the weighing is done by a physical beam balance, the buyer will have the same mass of sugar per kg both at the pole and at the equator.

    Find the reading of spring balance as shown in fig. Assume that mass M in equilibrium. (All surfaces are smooth).

    If parallel beam of light falls on a convex lens. The path of the rays is shown in fig. It follows that