A block of wood has a density of 650 kg/m³.When placed in water,what percent of the volume of the wood is above the surface? A) 0,the block sinks. B) 30% C) 35% D) 65%

Question

Quizplus · Accepted Answer

To solve the problem, we need to use Archimedes' principle, which states that the buoyant force on a submerged object is equal to the weight of the fluid displaced by the object.

First, we need to find the weight of the wood block:

Weight = Density x Volume x Gravity 
Weight = 650 kg/m^3 x V x 9.8 m/s^2 
Weight = 6370 V

Next, we need to find the buoyant force when the block is submerged in water:

Buoyant force = Density of water x Volume of submerged block x Gravity 
Buoyant force = 1000 kg/m^3 x V_sub x 9.8 m/s^2 
Buoyant force = 9800 V_sub

The block will float if the buoyant force is greater than the weight:

9800 V_sub > 6370 V 
V_sub/V > 0.65

Therefore, 65% of the volume of the block is submerged, which means that 35% of the volume is above the surface. So the answer is C.

A Block of Wood Has a Density of 650 Kg/m3

A Block of Wood Has a Density of 650 Kg/m³