An ingot bar made of Brass has a specific weight of 540lbft3

An ingot bar made of Brass, has a specific weight of 540lb/ft3 and a specific gravity of 8.48, with the dimensions of 15” x 4” x 2” (L x W x H). Find the (a) weight and (b) mass of the bar in USC and SI units. box in the answers

Solution

given

specific weight = 540 lb/ft3

specific gravity = 8.48

dimensions

length = 15 inches = 1.25 ft

width = 4 inches = 0.3334 ft

height = 2 inches = 0.1667 ft

we know that specific weight = weight / volume

weight = specific weight * volume

W =   540*1.25*0.3334*0.1667

W =   37.515 lbf ( usc units) Ans

1 N ( s.i unit) = 1/4.448 lbf ( usc units)

in si unit W = 37.515*4.448

W =   166.867 N ( s.i. units) Ans

we know that

specific gravity = density of substance/density of water

w = density of substance/1000

8.48 =   p(substance)/1000

density of substance = 8480 kg/m3 = 529.389 lb/ft3

we know that density = mass/volume

529.389 = mass/volume

mass =   529.389*1.25*0.3334*0.1667

mass m = 36.777 lb (usc units) Ans

1lb = 0.4536kg

mass m = 36.777*0.4536

mass m = 16.682 kg ( s.i. units) Ans

usc units s.i. units

(lbf/lb) (N/kg)

weight   37.515   166.867

mass   36.777 16.682