Question

The question i was given is: About how much pressure do the feet of a 6000-kg elephant exert on the ground? Assume each foot has an area of 0.10 square meter. Please show all your work.

so, i need to use the pressure formula p=force/area of application but, don't i need to convert the 6000kg in newtons first? how exactly would i go about doing that?

Answer 1

Yes, you need to convert the mass into weight first. The weight of the elephant is:

`W=mg = (6000 kg)(9.81 m/s^2)=5.89 \cdot 10^4 N`
This is the force that pushes on the ground. The total area on which this force is acting is 4 times the area of each foot (because the elephant has 4 feet), so the total area is:

`A=4 \cdot 0.10m^2 = 0.40 m^2`
And so, the pressure exerted by the feet of the elephant on the ground is

`p= (F)/(A) = (5.89 \cdot 10^4 N)/(0.40 m^2)=1.47 \cdot 10^5 Pa`