Physics 2

Question 1

Density

Density of water

Answer 1

D=m/v

Density of water=1g/cm^3

Question 2

Young’s modulus (elastic)

Answer 2

Y=(F/A)/(ΔL/L)
Measures the resistance of the solid to a change in its length when a force is applied PERPENDICULAR to its length
Tensile stress - lengthens rod
Compressive stress - shortens rod

Question 3

Shear Modulus (elastic)

Answer 3

Stress= Ft/A
Ft=tangential force
Strain = ΔX/h
ΔX -> cross sectional area
Measures the resistance of a solid to a shearing force
That is a force applied TANGENTIALLY to one of its surfaces

Question 4

Bulk Modulus (elastic)

Answer 4

Aka: Pressure
Applied to all phases 
P=Fn/A 
Fn=normal force 
Measures the resistance of a substance to a change in its volume

Question 5

In FLUIDS as depth increases, ________ increases

Answer 5

Pressure

Question 6

Pressure1 (p1) at some point relative to Pressure2 (p2) is determined by the difference in _________ between the two points

p1 =

Answer 6

Vertical height (h)

p1 = p0 + ρgh

ρ = density 
g = gravity 
h = height

Question 7

1 atm =

Answer 7

1 atm = 760 torr = 760 mmHg = 101,325 pascal

Question 8

(Units)

1 pascal =

Answer 8

1 pascal = 1 N/m^2

Question 9

Buoyant force

Fb =

Answer 9

An object is buoyed UP by a force = the weight of the fluid it displaces

Fb = ρVg

Question 10

Hydraulic lever equation

Answer 10

Fidi = Fodo

Force*distance

Question 11

Normal conversation is about _______dB

Answer 11

60

Question 12

Frequency range we can perceive

Answer 12

20-20,000 Hz

Question 13

I =

Intensity of wave

Answer 13

I = P/A

P= power 
A = cross sectional area 

If a sounds intensity is 10x it is perceived as being twice as loud

Question 14

Power (wave power)

Answer 14

P = IA

I = intensity 
A = cross sectional area

Question 15

Magnetic Force exerted on a charge

F =

Answer 15

F = qvB

q = charge 
v = velocity 
B = Magnetic field

Question 16

Magnetic force exerted on a current carrying wire

F =

Answer 16

F = ILB

I = current 
L = length of wire 
B = uniform magnetic field

Question 17

Right hand rule for magnetic force on CHARGE

Answer 17

Index = velocity 
Middle = Magnetic field 
Thumb = Force

Question 18

Right have (thumb) rule for magnetic field force on current carrying wire

Answer 18

Thumb = direction of current
(Opposite the direction or electricity)
Curl of fingers = direction of field lines

Question 19

Energy (EM wave)

E =

Answer 19

E = hf = hc/λ

Question 20

Refractive index (n) in relation to wavelength (λ)
n =

Answer 20

n =(λ vacuum)/(λ medium)

Question 21

Resistance

R =

Answer 21

R = ρL/A

ρ = resistivity 
L = length 
A = cross sectional area

Question 22

Heat energy (J) 
Q =

Answer 22

Q = mcΔT

m = mass in g
c = specific heat
ΔT = change in temperature

Question 23

For FLUIDS (gas or liquid)
Pt =
Pfluid =

Answer 23

Pt = Patm + Pfluid 
Pfluid = ρgh

Question 24

Specific gravity

S.G. =

Answer 24

S.G. = (ρsubstance)/(ρH2O)

ρ = density

Specific gravity has NO UNITS