Spring balances or spring scales measure weight (force) by balancing the force due to gravity against the force on a spring, whereas a balance or pair of scales using a balance beam compares masses by balancing the weight due to the mass of an object against the weight of a known mass or masses.
Net present value (NPV) or net present worth (NPW) is defined as the total present value (PV) of a time series of cash flows. It is a standard method for using the time value of money to appraise long-term projects.
DEFINITION of 'Net Present Value Rule'. A rule stating that an investment should be accepted if its net present value is greater than zero and rejected otherwise.According to the theory of net present value (NPV), participating in a positive NPV project will increase firm or shareholder wealth. rule stating that an investment should be accepted if its net present value is greater than zero and rejected otherwise.