Flashcards in Physics Deck (19):

1

## What is the equation for the energy of a photon of light?

### E=hf=hc/λ (J/photon)

2

## What is Plank’s constant?

### h=6.62 x 10^-34 Js

3

## What is the equation for the speed of light?

###
c=fλ= 3 x 10^8

4

## What direction to negatively charged particles move in an electric field?

### Opposite direction of electric field lines

5

## What is the equation for electric field produced by source charge Q?

###
E= kQ/r^2

direction= direction a +q would move in presence of source charge Q

6

## What is the equation for electrostatic force between 2 charges q and Q?

### F=kQq/r^2

7

## What is the equation for electric potential energy?

### U=kQq/r

8

## What is the equation for electric potential?

###
V=kQ/r

Electrons moves from higher potential (+) to lower potential (-)

9

## What is the value of k, Coulomb's constant?

### k=8.99 X 10^9 Nm/C^2

10

## What is the unit conversion for pressures?

### 1.013x10^5Pa = 760 mmHg = 760 torr = 1 atm

11

## What is the equation for the charge stored in a capacitor?

### Q=VC

12

## What is the equation for capacitance?

### C=ake/d

13

## What is the energy stored in a capacitor?

### U=1/2QV^2 = 1/2CV^2 = Q^2/2C

14

## When the battery is connected to the capacitor...

### V= constant; Q= changing

15

## When the battery is disconnected to the capacitor...

###
V= changing; Q= constant

Begin to discharge--> both start changing

16

## Sound Intensity

###
I= 10dblog(I/Io) Io= 10^-12

multiplying by 10= +10dB

dividing by 10= -10dB

multiplying by 1000= +30dB

sound waves spread out in all direction in a surrounding sphere; sound intensity decreases by a factor of r^2

17

## What is Hooke's Law?

###
(restoring force) F= kx

F vs displacement (x) is a linear relationship with k= slope

18

## What is the potential energy in a spring?

### PE= 1/2kx^2

19