Formulas

Question 1

gauge pressure formula

Answer 1

Pgauge = pgd

Question 2

flow speed and pressure

Answer 2

high flow speed has low pressure

Question 3

ratio of cross sectional area to speed of liquid flow in tubes

Answer 3

A1V1 = A2V2

Question 4

force acting on object moving underwater

Answer 4

Fnet = Fbuoy - mg
Fbuoy = pVg
mg = (p of object x V)g

Question 5

how density changes speed of emerging stream

Answer 5

same speed for all fluid

Question 6

viscosity is not in bernoulli’s equation

Answer 6

no term corresponding to production of heat

Question 7

E = qV
V = (kQ/r - kQ/r)

Answer 7

change in potential energy is same as energy to move charge from one place to another

Question 8

work required to move charge

Answer 8

equal to change in potential energy

if moving from 4cm to 3cm away in a different direction, same as moving from 4cm to 3cm

Question 9

when is electric field or electric potential between charges 0

Answer 9

electric field: halfway between charges

electric potential: never

Question 10

finding electric field vs electric potential between charges

Answer 10

field: find hypotenuse between and multiply by E of one
charge: add both

Question 11

magnitude of force charge would feel due to electric field

Answer 11

F=qE
if finding speed of proton and electron from same location, same q, but mass is different
a = F/m

Question 12

relationship between resistance and capacitance in a network

Answer 12

in a network, energy consumed by resistor network is equal to energy supplied by capacitance
can measure energy consumed by resistors by using formula for capacitance
Q=CV
PE = 1/2QV
PE = 1/2CV^2

Question 13

force felt between 2 charges

Answer 13

F = k q1q2/r^2

Question 14

k

Answer 14

9x10^9

Question 15

SI unit of charge e-

Answer 15

1.6x10^-19 C

Question 16

electric field created by a charge

Answer 16

E = kQ/r^2

Question 17

how charges move in conductor vs insulator

Answer 17

conductor: excess charge moves to opposite side of surface because they repel, no electric field is created and inside E= 0 because they cancel out
insulator: charged Q means it will become polarized

Question 18

current is

Answer 18

Q/t

Question 19

resistance changes depending on

Answer 19

R = pL/A
p: internal resistivity
A: area
L: length

Question 20

power is

Answer 20

I^2R

IV

Question 21

V is

Answer 21

IR
resistance remains constant at varying V
current reverses if V polarity reverses

Question 22

resistors in series

Answer 22

same current

R+R

Question 23

resistors in parallel

Answer 23

same voltage
RR/R+R
current going in + current coming out

Question 24

capacitors in series

Answer 24

same current

CC/C+C

Question 25

capacitors in parallel

Answer 25

same voltage | C+C

Question 26

measuring current or voltage

Answer 26

measure current in series - for internal resistance to be negligible, you want it small measure voltage in parallel - for internal resistance to be negligible you want it big

Question 27

what a capacitor is and what they're used for

Answer 27

pair of conductors that hold equal but opposite charge creates uniform electric field throughout V=Ed stores electrical potential energy

Question 28

charge on a capacitor, how to change capacitance

Answer 28

Q=CV C=EA/d C only changes with change in area, distance, or E: permitivity of free space

Question 29

how is Q=CV affected by dielectric if connected to a battery

Answer 29

Q increases to keep V at same level despite dielectric, increasing C

Question 30

how is Q=CV affected by dielectric if not connected to a battery

Answer 30

becomes polarized to lower V, which then increases C

Question 31

what happens to Q, C, V, electric field, and potential energy if capacitor is charged by battery, disconnected, and dielectric inserted

Answer 31

``` Q same cuz on battery C increases w dielectric so V goes down with V=Ed electric field decreases with PE=1/2QV PE also decreases where does PE go? some get stored as induced dipoles, some KE you feel when plates pull on dielectric ```

Question 32

what happens to Q, C, V, electric field, and potential energy if capacitor is charged, and dielectric is inserted while connected

Answer 32

V same cuz battery C increases, so Q increases in V=Ed, E doesn't change in PE = 1/2QV, PE increases

Question 33

dielectric breakdown

Answer 33

when electric field is so strong that dielectric becomes ionized and electrons flow