The intensity of a seismic wave crossing the Earth is measured at 2.5×10^6 J/m^2 at a distance of 43 km from the source. What was its intensity when it passed a point just 2.0 km from the source? AND How fast did the energy travel through an area of 4.0 m^2 at 2.0 km? Really need help with this problem please!!! Use the inverse square law. “intensity” is the total energy of the seismic wave per unit area.

2 km is 43/2 = 21.5 times closer than 43 km. The intensity will increase by a factor of 21.5^2=462. (This is where the inverse square law comes in). The intensity at 2 km is therefore 1.15*10^9 J/m^2. Multiply that by 4 m^2 for the total energy through that area. It will be a lot of energy. Billions of Joules would likely destroy any building on it