Question

A certain part of aircraft engine has a volume of

1.3ft3.
(a) Find the weight of the piece when it is made ofiron.
(b) If the same piece is made of aluminum, find the weight
anddetermine how much weight is saved by using aluminum instead
ofiron.

Answer 1

Answer: a) weight of iron = 638.94lb

b) weight of aluminium = 219.7lb

You have saved 419.24lb when you use aluminium rather than iron.

Step-by-step explanation:

The weight of an object of equal volume depends mostly on its density.

Density is the mass per unit volume of a material

density p = mass/volume = m/v

Mass m = density × volume = p × v

a) for iron the density of iron is 491.495lb/ft3

For 1.3ft3 of iron we have;

Mass = 491.495 × 1.3

Mass = 638.94lb

b) density of aluminium is 169lb/ft3

For 1.3ft3

Mass = 169 × 1.3

Mass = 219.7lb

c) the amount of weight we safe when we use aluminium is

= Mi - Ma

= 638.94 - 219.7

= 419.24lb

Answer 2

419.25 lbs

Step-by-step explanation:

Let iron density
`\rho_i` be 491.5 lb/ft3

and aluminum density
`\rho_a` be 169 lb/ft3

We can calculate the mass of iron that displaces 1.3ft3

`m_i = V*\rho_i = 1.3*491.5 = 638.95 lb`

Also the mass of aluminum that displaces 1.3 ft3

`m_a = V*\rho_a = 1.3*169 = 219.7 lb`

So by using aluminum, the airplane can save

638.95 - 219.7 = 419.25 lbs of weight