Question

Question:A glass of water contains floating ice cubes. When the ice melts, does the water level in the glass (a) go up, (b) go down, or (c) remain the same?

Short answer

When the ice melts, the water level in the glass remains the same. Hence the correct answer is option (c).

Step-by-step solution

Step 1: Archimedes’ principle

When an object is partially or fully submerged in a fluid, the fluid exerts on the object an upward force called the buoyant force. According to Archimedes’s principle, the magnitude of the buoyant force is equal to the weight of the fluid displaced by the object:

B =${\rho }_{Fluid}g{V}_{disp}$

Where V_dispthe volume of fluid is displaced and${\rho }_{Fluid}$ is the density of the fluid.

Find when the ice melts

F_{B =} W

Hereicedisplacedwaterequalstoitsvolume. Whenicecompletelymeltsthereisnochangeinvolume, hencethewaterlevelintheglassremainsame.

Hence the correct answer is option (c).