Question

A concrete column has a diameter of 350 mm and a length of 2 m. if the density (mass>volume) of concrete is 2.45 mg>m3, determine the weight of the column in pounds.

Answer 1

Density is defined as mass per unit volume. If we know the volume and he density we can calculate the mass by simply multiplying density and volume.

Density given = 2.45 mg/m^3 . [ I feel this should be Kg/m^3, Kindly check. Here I will solve it with what is given]

volume of cylinder = pi.r^2.h

r = d/2 = 175mm = 0.175m

h = 2m

Volume = 0.192 m square

mass = density x volume

mass = 0.192 x 2.45

= 0.470mg. {should be Kg if density is in Kg/m^3]

Answer 2

The weight of the column is 10.2pounds

Step-by-step explanation:

Step one

Given data

Diameter of column d=350mm

Radius =d/2=175m

length of column h =2m

Density of concrete =2.45 mg/m3

mg

The shape of the column is a cylinder

Volume of a cylinder =pi*r²*h

Volume of concrete =3.142*175²*2

Volume =192447.5m³

We know that the density of a substance is =mass/volume

First Let's find the mass

2.45*10^-6=mass/192447.5

mass=2.45*10^-6*192447.5

Mass=0.47149638kg

Mass=0.47kg

Converting to pound

1kg=2.20 5 pounds

0.47kg=x

Crosss multiplying we have

X=0.47*2.205

X=1.04pounds

But weight =m*g

Assuming g=9.81m/s

Weight =1.04*9.81

Weight =10.2pounds