# 1.2 Hydraulics Math

Given F=pA, solve for p in terms of F and A.

Given F=pA, solve for A in terms of F and p.

Given Q = V/t, solve for V in terms of Q and t

Given Q = V/t, solve for t in terms of v and Q

Comment on pressure and flow rate and how they influence the force and speed of a hydraulic actuator.

List units commonly employed to measure hydraulic quantities

 US SI/metric length area volume pressure force flow rate time

Determine equivalencies for the following values:

 1 in => cm 1 lbf => N 1 l => cm3 1 gallon => in3 14.5 psi => bar=> kPa 1 gallon => l

Convert a volume of 0.45 gallon to in3

Convert a volume of 40 in3 to gallons

Convert 650kPa to psi and bar

Convert 18 bar to psi and kPa

Convert 490psi to bar and kPa

Differentiate between the terms cap end, rod, and rod end with respect to area and volume. Draw a picture.

Which volume must be filled to extend a cylinder, the cap end, the rod, or the rod end?

Which volume must be filled to retract a cylinder, the cap end, the rod, or the rod end?

Write the formula used to determine the surface area of a circle.

Write the formula used to determine the surface area of a ring.

Write the formula used to determine the volume of a cylinder.

Write the formula used to determine the volume of a tube (a cylinder with a cylinder removed).

Given cylinder X with the following dimensions calculate the desired quantities:

dcap = 2 ¾ in

drod = ¾ in

travel length = 12 in

Acap =

Arod =

Arod end =

Vcap =

Vrod =

Vrod end =

Given a fixed flow rate of 0.75 gpm calculate the desired quantities for cylinder X:

textend (s) =

tretract (s) =

speedextend (in/s) =

speedretract (in/s) =

Given a pump with a fixed displacement of 0.4 in3/rev is rotated at 1800rpm calculate the flow rate in units of gpm.

Given a motor with fixed speed describe how flow rate can be varied.

Given a pump with fixed displacement describe how flow rate can be varied.

Given cylinder X calculate the desired quantities given the applied load is 2300lbf.

pextend =

pretract =

Given cylinder X calculate the desired quantities given maximum pressure is limited to 670psi.

Fextend MAX =

Fretract MAX = 