Energy . is used to do work
can't be converted from one form to another
can be created or destroyed​

the average speed is 24.57 km/hr

in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.