Final answer:
The Bernoulli equation is primarily used to calculate peak instantaneous velocity through the relationship between pressure and velocity for an incompressible, frictionless fluid.
Step-by-step explanation:
The Bernoulli equation is used to calculate peak instantaneous velocity. Bernoulli's equation, named after Daniel Bernoulli, states that for an incompressible, frictionless fluid, the sum of the pressure energy, kinetic energy per unit volume, and potential energy per unit volume is constant. This relationship allows for the measurement of fluid velocity using variations in pressure.
In more specific scenarios, like velocity measurement using a manometer, the equation simplifies to P1 = P2 + 1/2 pv², where P1 is the pressure where fluid velocity is zero and P2 is the pressure where the fluid has some velocity v.