Question

ONLY IITian's CAN DO THIS
please solve this question for me

Answer 1

Answer:

(b) 2.5×10^-3 m , downwards

Explanation:

Concept:

Melting ice doesn't rise the water level of it is freely floating.

In that case, according to Archimedes Principle, Weight is equal to the Buoyant force by water.

If we apply some extra force to submerge it more into the water, it will replace more water equal to the volume of ice submerged.

In this case, the extra force required will be equal to the Buoyant force of the forcefully displaced water and it causes to right the water level up (let say, h). So, if the ice melts the water level go the original level when the force is not there acting on the ice. Hence, the water level go down (say, h).

so,

Tension in the thread = Buoyant force of extra water

=> T = dVg

where, d - density of water

V - volume of extra water displaced

g - acceleration due to gravity

T - tension in the thread

since, V = Ah

T = dAhg

=> h = T / dAg = 1 / (400×10^-4 × 1×1000 × 10)

= 2.5×10^-3 m

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hope, it helps you.