ABSTRACT
This chapter considers the practical aspects of exploiting gravity measurements. It presents instruments for measuring weight and gravitational acceleration and discusses the ambiguity between weight and force measurements, units of gravitational acceleration. The chapter also discusses procedures for estimating a buried object's size, depth and density difference. It introduces a fundamental quantity known as the gravitational acceleration. It is important to realize that bathroom scales are only accurate so long as the Earth's gravitational acceleration is constant and the proper value is used in the scales' calibration. The gravitational force acting between these two masses is the product of the masses mM and varies inversely proportional to the square of their separation R. Since weight is the gravitational force equal to mass times the Earth's gravitational acceleration, and this acceleration is relatively constant, it can accurately be assumed that the concrete block has more mass than the wood block.
