Question

The gold bar has a trapezium cross section area (6+12) x 5/2. Gold has a density of 19.3 grams per cm^3.Work put the mass of the gold bar. Put your answer in kilograms

Answer 1

Explanation:

The volume of the gold bar= area of trapezium x length of gold bar

We know the length of the gold bar is 16 cm

Area trapezium formula: 1/2 (a+b)*h

So for the area of the trapezium: (6 + 12)*5 /2 which makes 45 cm^2

Volume of gold bar= 45cm^2 x 16 cm which makes 720^3 (links to the volume of gold bar formula)

We also know that the gold has a density of 19.3 g/cm^3

We know that the formula for density is: Density=mass/volume

Rearrange the formula for mass: mass=Density*Volume

Substitute the numbers: 720^3 g*19.3 g = 13986 g

Convert g into kg which you need to divide by 1000

13986/1000=13.986 KG

Hence, the mass of the gold bar is 13.986 KG or 13.99 KG (2 d.p)

I do hope this helps you out :)

Have a nice day!