KVPY2017PhysicsLaws of Motion
Four identical beakers contain same amount of water as shown below. Beaker 'a' contains only water. A lead ball is held submerged in the beaker 'b' by string from above. A same sized plastic ball, say a table tennis (TT) ball, is held submerged in beaker 'c' by a string attached to a stand from outside. Beaker 'd' contains same sized TT ball which is held submerged from a string attached to the bottom of the beaker.
Options
- AW_ a = W _ b = W _ c = W _ d
- BW_ b =W_ c >W_ d >W_ a
- CW_ b = W _ c > W _ a > W _ d
- DW _ b > W _ c > W _ d > W _ a
Correct answer
B. W_ b =W_ c >W_ d >W_ a
Step-by-step solution
(A) N _ A = Mg (B) aligned ( N _ B .&= ( M + M _ L ) g - T N _ B &= Mg + B aligned (C) N _ C = T + ( M + m _ T ) g Therefore N _ L = B - m _ T g + ( M + m _ T ) g N _ L = B + Mg (D) N _ D = ( M + m _ T ) g