Question

Calculate the pressure on the ground from an 80 kg woman leaning on the back of one of her shoes with a 1cm diameter heel, and calculate the pressure of a 5500 kg elephant with 20 cm diameter feet balancing on one foot.

Answer 1

Pressure of woman will be
`99.87* 10^5N/m^2`

Pressure of the elephant will be
`1716560.50N/m^2`

Step-by-step explanation:

We have given that mass of the woman m = 80 kg

Acceleration due to gravity
`g=9.8m/sec^2`

Diameter of shoes = 1 cm =0.01 m

So radius
`r=(d)/(2)=(0.01)/(2)=0.005m`

So area
`A=\pi r^2=3.14* 0.005^2=7.85* 10^(-5)m^2`

We know that force is given F = mg

So
`F=80* 9.8=784N`

Now we know that pressure is given by
`P=(F)/(A)=(784)/(7.85* 10^(-5))=99.87* 10^5N/m^2`

Now mass of elephant m = 5500 kg

So force of elephant = 5500×9.8 = 53900 N

Diameter = 20 cm

So radius r = 10 cm

So area will be
`A=3.14* 0.1^2=0.0314m^2`

So pressure will be
`P=(53900)/(0.0314)=1716560.50N/m^2`