Question

If the ultimate shear strength of steel is taken to be 3.00 109 Pa, what force is required to punch through a steel plate 1.60 cm thick? Assume the superhero's fist has cross-sectional area of 1.20 102 cm2 and is approximately circular. Qualitatively, what would happen to the superhero on delivery of the punch? What physical law applies?

Answer 1

Step-by-step explanation:

Given

Ultimate shear strength
`\tau =3* 10^9\ Pa`

thickness of steel Plate
`t=1.60\ cm`

Cross-sectional
`A=1.20* 10^2\ cm^2`

suppose d is the diameter of cross-section

`(\pi )/(4)d^2=1.20* 10^2`

`d=12.359\ cm`

Shear area of circular cross-section

`A_s=\pi dt`

`A_s=\pi * 12.359* 1.6`

`A_s=62.13\ cm^2`

Shear Force
`F_s=A_s* \tau`

`F_s=62.13* 10^2* 3000`

`F_s=18.639\ MN`