Fluids

A boat floats in both fresh water (ρ=1000kg/m³) and in salt water(ρ=1025 kg/m³). Where is the buoyant force greater ?

• In salt water

• In fresh water

• The same in both salt water and fresh water

• More information is needed

A steel ball sinks in water but floats on mercury. Where is the buoyant force of the ball greater?

• Floating on mercury

• The same for both cases

• Submerged in the water

• It cannot be determined

As a rock sinks deeper and deeper into water, what happens to the buoyant force on it if it started above the surface?

• The buoyant force keeps increasing steadily

• The buoyant force remains constant

• The buoyant force first increases and then remains constant

• The buoyant force decreases

Buoyant force is equal to...

• Volume of the displaced fluid

• Weight of the displaced fluid

• Mass of the object

• Weight of the object

A ball has a mass of 100 grams and a volume of 20 cm³. What is the density?

• 5 kg/m³

• 50 kg/m³

• 500 kg/m³

• 5000 kg/m³

An object has a density of 784 kg/m³. Will it sink or float on water?

• Sink

• Float

An object has a density of 1320 kg/m³. Will it sink or float on water?

• Sink

• Float

When an object floats, the object's density is greater than the density of the fluid on which it floats.

• True

• False

When an object floats, the object's density is equal to the density of the fluid on which it floats.

• True

• False

The bouyant force of an object that floats is equal to the object's weight

• True

• False