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Do you think it is possible for giants exist? Consider the human femur, or thighbone. It is the strongest bone in the body. The femur of an average adult man is 48 cm long and has a diameter of 2.34 cm. It can support up to 30 times the weight of an adult. If a giant was 5 times larger than an average man, in each dimension, do you think the femur could support the giant's

User Oji
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Let us assume that the top of the femur is circular. We would calculate the cross sectional area by applying the formula,

Area = πr^2

where

π = 3.14

r = radius

Given that diameter = 2.34,

radius = diameter/2 = 2.34/2

radius = 1.17

Cross sectional area = 3.14 x 1.17^2 = 4.298 cm^2

Given that the length = 48cm,

volume = 48 x 4.298 = 206.304 cm^3

206.304 cm^3 can support 30 times the weight of the adult. Thus,

ratio of volume to weight = 30

206.305/weight = 30

206.305 = 30 x weight

weight = 206.305/30 = 6.88

If the giant is 5 times larger than the average adult, it means that

radius of the giant's bone = 5 x 1.17 = 5.85

Area = 3.14 x 5.85 = 18.369

length of femur = 48 x 5 = 240

Volume of the giant's femur = 240 x 18.369 = 4408.56

This means that 4408.56 cm^3 should support 30 times the giants weight

Thus,

Weight of the giant = 5 times the weight of the adult

Weight of the giant = 5 x 6.88 = 34.4

Dividing the volume by the weight, we have

4408.56/34.4 = 128.15

This is more than 30

Now, the ratio of the giant's weight to the normal adult's weight should be 5. We have

146.952/6.88 = 128

This means that the femur can support up to 128 tims the weight of the giant. Since it is more than 30, then, the femur could support the giant's weight.

User Ajames
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