Sending short pulses of electromagnetic waves into the ground and then receiving reflections of these waves to detect underground changes in soil or archaeological features is known

Ground Penetrating Radar (GPR)

Explanation:

Ground Penetrating Radar is a non-destructive testing method that uses electromagnetic radiations of the microwave band range of very high frequency and detects them after the reflection from the subsurface.

It is a geophysical method of subsurface imaging.

It is used to study the underground water, bedrocks, archaeological artifacts and features, detection of unexploded ordnance and detecting tunnels.

grav forces affect all objects magnetic forces affect magnetic objects and electric currents

0 = 0.40 / 0 = 0

= 0.20 = 9.80 ⁄2 =?

=0 , = = 0.20 =0.50 0 0.40 ⁄

=0−122 =0−12(9.80 ⁄2)(0.50)2 =1.2