Archimedes' Principle

An object in water experiences buoyant force if it (a)  

• it has no weight.

• it is denser than water.

• it displaces water.

• it repels water.

Answer explanation

An object experiences buoyant force when it displaces water. According to Archimedes' principle, the buoyant force is equal to the weight of the water displaced by the object, regardless of its weight or density.

An object that displaces water equal to its weight will…

• sink.

• float on top.

• remain at the water level.

• dissolve.

Answer explanation

An object that displaces water equal to its weight is in equilibrium with the buoyant force. This means it will neither sink nor float but remain at the water level.

What would happen if the density of a boat increased too much?

• The boat would float higher.

• The boat would displace more water.

• The boat would sink.

• The boat would stay afloat longer.

Answer explanation

If the density of a boat increases too much, it means the boat is heavier relative to the water it displaces. This can cause the boat to sink, as it can no longer displace enough water to support its weight.

Which factor is most directly related to sinking or floating?

• Surface area

• Object’s density relative to water

• Temperature of the object

• Shape of the object

Answer explanation

The factor most directly related to sinking or floating is the object's density relative to water. If an object's density is less than that of water, it will float; if greater, it will sink.

What happens to an object that displaces less water than its weight?

• It floats.

• It remains suspended in water.

• It sinks.

• It rises above water.

Answer explanation

An object that displaces less water than its weight cannot generate enough buoyant force to stay afloat, causing it to sink. Therefore, the correct answer is that it sinks.

If the weight of displaced water is more than the object’s weight, the object will (a)  

• dissolve.

• stay on the surface.

• sink slowly.

• float.

Answer explanation

If the weight of displaced water is greater than the object's weight, it means the buoyant force is sufficient to keep the object afloat. Therefore, the object will float.

affects buoyancy.

• Water colour

• Object's density

• Object's shape only

• Water temperature

Answer explanation

Buoyancy is primarily affected by an object's density. An object will float if its density is less than that of the fluid it is in, while it will sink if its density is greater. Water color and temperature do not directly affect buoyancy.

Archimedes' Principle states that... 

• The buoyant force acting on an object equals the volume of the fluid displaced by the object. 

• The buoyant force acting on an object equals the weight (force of gravity) of the fluid displaced by the object.

• The buoyant force acting on an object will always be equal. 

The upward force exerted by a liquid on an object immersed in or floating on the liquid

• pressure

• buoyant force

• normal force

• gravity

The buoyant force on floating objects equals the weight of the floating object 

• true

• false