Equations

Question 1

Big Five #2

missing d

Answer 1

v = v0 + at

Question 2

Big Five #3

Missing v

Answer 2

d = v0t + 0.5at^2

Question 3

Big Five #5

missing t

Answer 3

(v^2) = (v0^2) + 2ad

Question 4

Newton’s first law

Answer 4

If Fnet = 0, change in v = 0

An object in motion will stay in motion unless acted upon by an outside force

Question 5

Newton’s second law

Answer 5

F = ma

Question 6

Newton’s third law

Answer 6

For every action there is an equal and opposite reaction

I.e. The force exerted by A on B will be equal and opposite to the force exerted by B on A

Question 7

Work (Newtonian)

Answer 7

W = Fdcosθ, units: J

Angle is between F and direction of motion

Work-energy theorem: Wtot = ΔKE

P = W/t, units: Watts

Question 8

Thermodynamics

Answer 8

ΔE = Q - W

W = PΔV

V = free space in the vessel

W = area under curve on PV diagram

W and Q are path-dependent

Question 9

Buoyant force (Archimedes’ principle)

Answer 9

Fbuoy = (ρfluid)(Vsub)g = Wobj

Vsub/V = ρobj/ρfluid

Question 10

Continuity equation

Answer 10

A1v1 = A2v2

The rate at which a fluid enters a system is equal to the rate at which the fluid exits the system

Question 11

Electric field/force relation

Answer 11

Fe = qE (force exerted by a field on a point charge)

E = kQ/(r^2) (field due to a point charge); units = N/C or V/m

Question 12

Electric potential energy/potential relation

Answer 12

ΔPE = qΔφ = qV

φ = kQ/r, units: C/m

Work done by field = -ΔPE

Question 13

Ohm’s Law

Answer 13

V = IR

Question 14

Period/frequency relationship (waves)

Answer 14

f = 1/T

T = 1/f

Small angle approx for pendulum: not dependent on mass

Question 15

Doppler effect

Answer 15

fd = fs(v + or - vd)/(v - or + vs)

If s and d are getting closer, use top signs

Question 16

Snell’s Law

Answer 16

n1sinθ1 = n2sinθ2

n = c/v

sin(θc) = n2/n1

Question 17

Mirror/lens equations

Answer 17

(1/o) + (1/i) = (1/f)

m = (-i/o)

P = 1/f

Question 18

Mirror/lens conventions

Answer 18

Concave mirror/convex lens: +f, can produce real or virtual images

Convex mirror/concave lens: -f, only produce virtual images

-i = virtual, upright
\+i = real, inverted

Question 19

Henderson-Hasselbach

Answer 19

pH = pKa + log([A-]/[HA])

Question 20

Galvanic cell

Answer 20

Cathode: reduction
Anode: oxidation

Standard conc. is 1 M in each half cell

If both cells use the same element, E = 0

ΔG = -nFE

Question 21

Impulse

Answer 21

J = FΔt = ΔP

P = mv

Question 22

Springs

Answer 22

Fs = -kx

W = (kx^2)/2

Question 23

Sound

Answer 23

dB = 10log(I/Io)

For every 10 dB increase, a sound is 10x more intense

I = P/A

Question 24

Torque

Answer 24

T = rFsinθ

θ measured as if F and r originate at the same point, always <180

Question 25

Gibbs’ free energy

Answer 25

ΔG = ΔH - TΔS

Thermodynamic, not kinetic

\+ΔG = nonspontaneous
-ΔG = spontaneous

Standard ΔG = -RTlnKeq

Question 26

Circuit conventions

Answer 26

Series:

• R is summative
• C is inversely summative
• I is constant
• C is summative

Parallel:

• R is inversely summative
• C is summative
• I is summative
• V is constant

Question 27

Friction

Answer 27

Ff = μFn

μk < μs

Question 28

Uniform circular motion

Answer 28

Fc = ma = m(v^2/r)

Question 29

BDE

Answer 29

E(separate atoms) - E (bonded)

= 0 - E

E(bonded) always - so BDE always +

Breaking a bond requires energy

Question 30

Capacitance

Answer 30

C = κεA/d

PE = CV^2/2 = Q^2/2C

Question 31

Types of decay

Answer 31

α: lose 4 mass units and 2 protons

β: lose an electron (atomic # increases)

Neutron capture: mass # increases

Electron capture: electron combines with proton, mass # same but atomic # decreases

γ: photon emission

Question 32

Dalton’s Law

Answer 32

Sum of partial pressures of gases in a mixture equals the total pressure of the mixture

Partial P = mole fraction x Ptot
Py = XyPtot

ppm = mole fraction x 1,000,000

Question 33

Venturi effect

Answer 33

When fluid flows through a narrow section of the container, pressure drops

Question 34

Boyle’s Law

Answer 34

At constant temperature, pressure and volume for an ideal gas are inversely related