THINGS YOU SHOULD REALLY MEMORIZE

1. Weight does not equal mass!!!!

W = mg

W = Newtons

1 kg = 2.2 lbs

Mass of average high schooler = 65 kg

Weight of average high schooler = 650 N

2. Slope = rise over run = Δy/Δx…make sure you put in units.

DO NOT JUST COUNT BOXES!

3. Inverse square law: Applies to gravity and electrostatic forces…

not to the nuclear force.

Strong Nuclear Force range = 10-15 m

4. Long, thin, & hot wires have a high resistance and allow little

current to flow.

R = V I

5. The two left hand rules for magnetism.

Fingers = magnetic field linesThumb = direction of current flow

Palm = direction of magnetic force

SN

B

e-

In which direction would this electron be forced if it entered this magnetic field traveling upward?

#1- Magnets

#2- Around a Wire

6. Gravitational, Electric, and Magnetic Field lines never cross, leave & enter perpendicular, and are stronger when

they are closer together.

7. Magnetic Field goes from North to South.

8. Electric Field goes from positive to negative.

-

+

9. Current flow from negative to positive.

10. Longitudinal waves (sound) disturbance is parallel. Transverse waves (light)

disturbance is perpendicular.

11. Refraction- Bends towards the normal going from a less dense to a more dense medium. The speed changes…not the

frequency.

12. Doppler effect- when something is approaching, the apparent frequency goes

up and the wavelength goes down.

13. Energy level diagram in modern (hydrogen and mercury atoms). It takes energy (absorb a photon) to move up the diagram. When you go down the

diagram, you emit a photon (release energy).

ABSORB EMIT

14. Violet has more energy than red.

Why? Because violet has a higher frequency and frequency is related to energy by E = mc2.

15. Nuclear Force is the strongest, but only at short distances.

Force Relative Strength

Range of Force

Force Carrier

Mass Charge

Strong

(nuclear)

1 10-15 m gluon 0 0

Electro-

magnetic

10-2 Proportional to 1/r2

photon 0 0

Weak 10-13 <10-18 m W boson

W boson

Z boson

80.6 eV

80.6 eV

91.2 eV

+ e

- e

0Gravitational 10-38 Proportiona

l to 1/r2graviton 0 0

Shorthand:

• Mag Field N S

• Elec Field + -

• Current - +

• Long (sound) II w/ velocity

• Trans (light) ├ w/ velocity

• Doppler Towards- f Away- f

Graphing:

• Units when finding slope

• Find slope from best fit line not from data table

• No breaks

• Typically start at zero

• Be careful of ind/dep vs. formula for axis and finding slope

• Use a ruler to draw best fit line

How to answer a two point question:[show all work, including the equation

and substitution with units] [2]

Four ways to lose points!!!!

1. Formula…does not have to be solved for the unknown

2. Substitution…make something up if stuck

3. Units…in substitution and answer

4. Answer…check using calc and logic (does it make sense???)

General:

• Put an arrow head on vectors…measure to the tip• Cross off bad choices• Follow directions• Use the tables/know the tables• Use calculator and paper for math• When required, draw a picture and write an

unknown/given• Be thorough with written answers…more is better on the

Regents• You know more than you think…be confident• Use scrap…but make sure answers with work are on the

answer paper.

Bring:

• cm ruler

• Protractor

• Calculator w/ fresh batteries

• Pen-blue or black

• Pencils