Answer
(a) Pound for pound, tendon is stronger than steel under tension.
(b) Pound for pound, concrete is stronger than bone under tension.
Work Step by Step
(a) We can find the ratio of tensile strength to the density of tendon:
$\frac{80.0\times 10^6~N/m^2}{1100~kg/m^3} = 72,700~m^2/s^2$
We can find the ratio of tensile strength to the density of steel:
$\frac{0.50\times 10^9~N/m^2}{7700~kg/m^3} = 64,900~m^2/s^2$
Pound for pound, tendon is stronger than steel under tension.
(b) We can find the ratio of tensile strength to the density of bone:
$\frac{160\times 10^6~N/m^2}{1600~kg/m^3} = 100,000~m^2/s^2$
We can find the ratio of tensile strength to the density of concrete:
$\frac{0.40\times 10^9~N/m^2}{2700~kg/m^3} = 148,000~m^2/s^2$
Pound for pound, concrete is stronger than bone under tension.
