Yes, you need to convert the mass into weight first. The weight of the elephant is:
[tex]W=mg = (6000 kg)(9.81 m/s^2)=5.89 \cdot 10^4 N[/tex]
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:
[tex]A=4 \cdot 0.10m^2 = 0.40 m^2[/tex]
And so, the pressure exerted by the feet of the elephant on the ground is
[tex]p= \frac{F}{A} = \frac{5.89 \cdot 10^4 N}{0.40 m^2}=1.47 \cdot 10^5 Pa [/tex]
