Amaterial will float on the surface of a liquid if the material has a density less than that of the liquid. given that the density of water is approximately 1.0 g/ml, will a block of material having a volume of 1.3 104 in3 and weighing 350 lb float or sink when placed in a reservoir of water?

We will first convert lb to grams and in³ to milliliters. 
350 lb : 2.205 = 158.75733 kg = 158,757.33 grams
1.3 · 10^4 in³ = 13,000 in³ = 13,000 · 0.016387064 = 213.031 liters 
213.031 liters · 1,000 = 213,031 milliliters
Density = m / V = 158,753.33 g / 213,031 ml = 0.7452 g/ ml
A block of material will float.

Answer: buoyancy forceexplanation: 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.