All Equations

Question 1

Stored energy/ Potential energy moving object

Answer 1

1/2 mass x velocity [squared]

Question 2

metabolic contents

ie. Energy released when 1 Kg glucose is metabolised to CO2 and water (the metabolic energy content of glucose is approximately 16 kJ g-1)

Answer 2

convert all to grams.

relates to the metabolic energy content of carbohydrate = 1000 x 16 000 = 16 MJ

Question 3

Energy used in heating

ie. Raising the temperature of 25 Kg water from 0 ° C to 100 ° C (the specific heat capacity of water is approximately 4 kJ per Kg per ° C)

Answer 3

relates to specific heat capacity = mass x SHC x temperature change.

convert to grams for ° C or all to joules

= 25 x (4 x 1000) x 100 = 1, 000, 000 / 100, 000 = 10 MJ

Question 4

Potential energy of a mass raised

ie. Raising a 1000 Kg mass to a height of 1 Km against gravity (acceleration due to gravity = g = 10 m s-2)

Answer 4

relates to potential energy = mass x gravity x height

= 1000 x 10 x 1000 = 10 MJ

Question 5

electrical energy?

ie. The heat generated when a direct current of 10 amps flows through a heating element for 100 seconds when the potential difference across the element is 10 000 volts

Answer 5

Power = VI or I [squared] R (seconds)

relates to electrical energy = IV x seconds = 10 x 10 000 x 100 = 10 MJ

Question 6

Vd?

Answer 6

D / C

Dose / concentration at time zero

OR

T = Vd/ Cl therefore Vd = time constant x clearance

Question 7

time constant?

Answer 7

= 1/ rate constant

OR

= Vd/ Clearance

Question 8

Clearance?

Answer 8

Vd / time constant

Question 9

Loading dose?

Answer 9

Vd x plasma concentration

Question 10

Maintenance dose?

Answer 10

plasma concentration x clearance

Question 11

pressure

Answer 11

force / area

Question 12

Reynolds number

Answer 12

          viscosity

lower reynolds ( <2000) = laminar

Question 13

Hagen- Pouseuille Equation

Answer 13

For laminar flow.

         Pi x pressure x diameter^4 Flow = -----------------------------------------------------
           128 x viscosity x length

Question 14

Boyle’s Law

Answer 14

K - constant

PV = K

Question 15

Charles Law

Answer 15

K = V/T

Question 16

3rd gas law

Answer 16

P/T = K

Question 17

Universal Gas Law

Answer 17

PV = nRT

R - universal gas constant
n - number of moles

Question 18

Charge

Answer 18

amperes x seconds

Question 19

Voltage?

Answer 19

V = IR

Question 20

Capacitance?

Answer 20

Q/V

Question 21

Defibrillator stored energy

Answer 21

0.5 CV [squared]. (c - capacitance)

OR

0.5QV

Question 22

Work done

Answer 22

force x distance

Question 23

Wheatstone Bridge

Answer 23

R1 R3
—- = —-
R2 R4

Question 24

Resistors in parallel

Answer 24

1/ R = 1/R1 + 1/R2 + 1/R3

Question 25

Resistors in series

Answer 25

R1 + R2 + R3

Question 26

Volume in a compartment?

Answer 26

mass of indicator

conc. in compartment

Question 27

plasma osmolality?

Answer 27

2 Na + glucose + urea

Question 28

SV?

Answer 28

EDV - ESV

Question 29

Ejection fraction?

Answer 29

SV / EDV

Question 30

Cardiac output?

Answer 30

HR X SV

Question 31

Cardiac index?

Answer 31

BSA

body surface area

Question 32

SVR?

Answer 32

MAP - CVP
—————- X 80
CO

Question 33

MAP?

Answer 33

MAP - CVP = CO X SVR

therefore

MAP = (CO X SVR) + CVP

Question 34

Blood Oxygen content

Answer 34

= (1.39 x Hb x sats) + (0.023 x PO2)

Question 35

Urinary Clearance

Answer 35

Cl = urine flow( ml/min) x urine conc
——————————————–
plasma concentration

Question 36

CPP

Answer 36

CPP = MAP - (ICP = CVP)

Question 37

Energy?

Answer 37

Energy = force x distance

Question 38

atmospheric pressure is equal to:
? cm H20
? mmHG

Answer 38

10 m H20

760 mm Hg

Question 39

Triple point of water

Answer 39

0.006 Bar

273 K