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
q4. a piece of foam is pushed underwater but pops back up. why?
a. it is denser than water
b. it is less dense than water
c. it has the same density as water
d. it has no mass
q5. which object would float in both oil and water?
a. rock
b. cork
c. steel ball
d. glass
fill-in-the blanks
part b – fill-in-the-blank (5 questions)
q6. if an object is ____ dense than water, it will float.
q7. oil floats on water because it is ____ dense than water.
q8. objects that sink in water have a density that is ____ than wa
q9. ice floats in water because its density is slightly ____ than w
q10. density is the relationship between ____ and volume.

Explanation:

Q3

An object sinks in a fluid when its density is greater than the fluid's density. Since the glass marble sinks in water, its density must be higher than water's. Option A is wrong (less dense would float), C is wrong (all matter has density), D is wrong (density matters for floating/sinking).

When an object pops back up in water, it means the buoyant force (related to density) is greater than its weight. An object less dense than water will float (or pop up when pushed down). Option A is wrong (denser would sink), C is wrong (same density would stay suspended), D is wrong (all matter has mass).

To float in both oil and water, an object must be less dense than both. Rock, steel ball, and glass are denser than both (so sink). Cork is less dense than both oil and water, so it floats in both.

Answer:

B. The marble is denser than water

Q4