Question

q3. a glass marble sinks in water. which is correct? a. the marble is less dense than water b. the marble is denser than water c. the marble has no density d. density does not matter

Explanation:

To determine why a glass marble sinks in water, we use the concept of density. An object sinks in a fluid when its density is greater than the fluid's density. Water has a known density, and if the marble sinks, its density must be higher than water's. Option A is incorrect (less dense would float), C is incorrect (all matter has density), and D is incorrect (density determines buoyancy). So the correct reasoning leads to option B being wrong and the correct answer is B? Wait, no—wait, if it sinks, the marble is denser. Wait, let's recheck: The principle is: if an object's density ($
ho_{object}$) > density of fluid ($
ho_{fluid}$), it sinks; if $
ho_{object}$ < $
ho_{fluid}$, it floats. So for the marble to sink in water, $
ho_{marble}$ > $
ho_{water}$. So option B says "The marble is denser than water"—wait, the options: A is less dense, B is denser, C is no density, D is density doesn't matter. So the correct answer is B? Wait, no—wait, the question is "Which is correct" about the marble sinking. So the correct statement is that the marble is denser than water (because that's why it sinks). So option B is "The marble is denser than water"—so that's correct.

Answer:

B. The marble is denser than water