Physics Flashcards

Question

acceleration of uniform circular motion =?

Answer 1

F_c=ma_c=mv²/r

Answer 2

Ƭ = rFsinΘ

Answer 3

torque is a measure of a force's effectivness at making an object spin or rotate (accelerate rotationally)

Answer 4

Resistance to rotational acceleration

Answer 5

Close together

Answer 6

Ƭ_net= Iα I is rotational inertia alpha is rotational acceleration

Answer 7

The inertia will be smallest when the rotation axis passes through the objects center of mass

Answer 8

Solid ball - therefore it would roll more easily than the hollow ball

Answer 9

P = W/t work/time

Answer 10

change in KE

Answer 11

mgh (if height increases) -mgh (if height decreases)

Answer 12

E= KE + PE

Answer 13

KE + PE = KE₂ + PE₂

Answer 14

total mechanical E is not conserved. KE + PE + W_{by F}= KE₂ + PE₂

Answer 15

MA = d_effort/d_resistance

Answer 16

The ramp takes less force but the work ends up being the same

Answer 17

W_output/E_input

Answer 18

Conduction - direct transfer of E (touching the hot stove) Convection - E transferred like a fluid (candle warming air) Radiation - Absorption of E via light waves (sun warming)

Answer 19

kg • m/s

Answer 20

Yes - it includes direction!

Answer 21

p=mv | (momentum)

Answer 22

N • s | (second)

Answer 23

Δp=Δmv=FΔt

Answer 24

m₁V₁ + m₂V₂ = m₁V₁^'+ m₂V₂^'

Answer 25

1. elastic - total momental & total KE conserved 2. Inelastic - total momentum conserved NOT total KE 3. Perfectly inelastic: obejcts stick together afterwards. momentum is conserved. Elastic collision is the only one KE is conserved in

Answer 26

3 m/s 8kg \* 5m/s + 2kg \* -5 m/s = 10kg \*?

Answer 27

L = lmv = Iw (el)mv (eye)w Just multiply linear momentum by length (p=mv)

Answer 28

greater J = Δp

Answer 29

L=lmv = Iw l (el) is lever arm, m is mass, v is velocity I(eye) is moment of inertia, w is angular velocity L is angular momentum

Answer 30

If net torque is 0, then total angular momentum doesn't change L_i=L_f I_iw_i=I_fw_f

Answer 31

She pulls her arms closer to the axis of rotation, so her moment of inertia decreases and her angular velocity increases (she spins faster)

Answer 32

p (but the p has a tail)

Answer 33

kg/m³ or g/cm³

Answer 34

1000 kg/m³ or 1 g/cm³

Answer 35

How dense something is compared to water Specific gravity = p/p_h2o

Answer 36

acceleration

Answer 37

kg•m/s²

Answer 38

(I)(alpha) torque = rotational inertia \* rotational acceleration

Answer 39

Side, inertia is smallest when passing through center of mass

Answer 40

torque = rFsinØ if torque is perpendicular to r, then torque=rf

Answer 41

Solid ball, because it has smaller rotational inertia, the rotation axis passes through the center of mass

Answer 42

scalar, it has no direction

Answer 43

W=Fd | (force \* distance)

Answer 44

How fast work gets done

Answer 45

P = W/t work/time P=Fv

Answer 46

KE + PE = KEf + PEf

Answer 47

J=►p=►mv=F►t

Answer 48

Li=Lf = Iiwi = Ifwf (initial momentum = final momentum) (Initial rotational inetial \* initial angular velocity = finals)

Answer 49

F_B=pVg (density\*volume that's submerged\*gravity)

Answer 50

F₁/A₁=F₂/A₂

Answer 51

f=Av area\*velocity

Answer 52

P₁ + 1/2pv₁² + pgy₁= P₂ + 1/2pv₂² + pgy₂ _{p is density of flowing fluid} _{v is velocity} _{y is height above horizoantl reference} _{P is pressure}

Answer 53

V_efflux= Í2gD (square root of ) D = y1-y2

Answer 54

F/A force/area (the difference between pressure is pressure must be perpendicular to the object it acts on)

Answer 55

►L/L₀ _{tensile/ compressive strain is stretching or squeezing}

Answer 56

x/L₀ shear strain is bending x=distance of shear/bend

Answer 57

stress = modulus x strain (modulus is a constant) F=kX

Answer 58

tensile and compressive stress ►L = FL₀/EA (FLEA!) (E is modulus, unit is pascal)

Answer 59

(bending!) X= FL₀/AG (FLAG!!) G is modulus

Answer 60

electric charge of proton or neutron 1.6 x10^-19 C

Answer 61

q = n(+- e)

Answer 62

6.02\*10²³

Answer 63

k q₁+q₂/r² k is proportionality constant, usually = 9\*10⁹ N\*m²/C²

Answer 64

away toward

Answer 65

F = qE q is the charge that feels the field E is in N/C

Answer 66

V = k Q/r Ø unit is volt!!

Answer 67

lower Potential

Answer 68

higher potential

Answer 69

net movement of charge

Answer 70

I = Q/t units of current is c/s

Answer 71

R= V/I = p L/A (voltange/resulting current) p is resistivity which is intrinsic resistance L is length A is cross sectional area

Answer 72

series: R = R1 + R2.. parallel: R1R2/R1 + R2

Answer 73

Pair of conductors that can hold equal but opposite charge

Answer 74

Q=CV C is a constant, capacitance, unit F ( farad)

Answer 75

the "capacity" for holding charge

Answer 76

PE = 1/2 QV Q is charge on the capacitor V is voltage

Answer 77

current (I) voltage ((in a book series, the main character (I) is the same)

Answer 78

Dialetric, it is insulating material

Answer 79

it feels no force

Answer 80

F_B= q (v \* B) v is velocity of charge q B is magnetic fieldc

Answer 81

solenoid a magnetic field, parallel to central axis

Answer 82

F = -kx F is force exerted by spring k is constant. the greater it is, the stiffer the spring x is string's displacement

Answer 83

period, time it takes to complete one cycle (spring)

Answer 84

f = 1/T T is period ( in seconds)

Answer 85

v = wavelength \* frequency f is constant - see big rules. wave speed is dependent on wavelength MCAT LOVES WAVES

Answer 86

The speed of a wave is determined by the type of wave and the characteristics of the medium NOT by the frequency

Answer 87

When a wave passes into another medium, its speed changes but its frequency does not

Answer 88

How much E the wave transports. It has nothing to do with anything else

Answer 89

1/2wavelength

Answer 90

Fastest through solids, then liquids, then gases

Answer 91

energy the sound wave transmits per second (power) per unit second, it is w/m² w is watt

Answer 92

The sound level.

Answer 93

f_D=f_s v+-v_D/v-+v_s fD is frequency heard by detector fs is frequency emitted by source v is speed of wave vd is speed the detector is moving vs is speed source is moving

Answer 94

1/o + 1/i = 1/f o is object's distance from the mirror (ALWAYS positive) i is image's distance from the mirror f is focal length of mirror

Answer 95

on the same side as the human observer (but in lens oppostie sides)

Answer 96

real virtual

Answer 97

m = -i/o m + then image is upright m - then image is inverted

Answer 98

P = 1/f f is focal length in meters power unit is diopeter

Answer 99

farsightedness (can't focus near)

Answer 100

near sightedness (can't focus far away)

Answer 101

converging

Answer 102

horizontally

Answer 103

horizontal

Answer 104

y=v₀t + 1/2(-g)t²

Answer 105

v_y=v_0y + (-g)t

Answer 106

F_grav=G Mm/r²

Answer 107

Fgrav=G Mm/r² If distances is doubled, then r increases by factor of 2, and Fgrav will decrease by factor of 2² = 4

Answer 108

If distance is cut in half, then r decreases by factor of 2 and Fgrav wil increase by factor of 2² = 4. Fgrav=G Mm/r²

Answer 109

g=GM/r² g depends on radius and mass M is mass r is radius G is universal constant

Answer 110

Kinetic: experimentaly determined + number with no units the greater the number, the greater the force of kinetic friction Static: There's a max between 2 surfaces it is always larger than coefficient of kinetic friction can only compute its max force (F_fmax=u_sF_N)

Answer 111

a = 5m/s² t=2s See green star page for how to calculate

Answer 112

7.5m/s² See green star page for how to do

Answer 113

a_c= v²/r

Answer 114

Ia I = rotational inertia a = rotational acceleration Like F=ma! I is like mass, a is accerleration

Answer 115

a. gravitational, local (PE = mgh) b. spring (PE = kx² /2) c. gravitational, general (PE = –GmM/r)

Answer 116

if CCW + if CW -

Answer 117

No, it is a property of a force, it is a mesasure of the effectivness of a force at making an object spin or rotate.

Answer 118

Yes, speed is constant. But, velocity is a vector - so it keeps changing b/c it is going in a circle, therefore it is undergoing acceleration

Answer 119

torque = lF | (lever arm and force)

Answer 120

translational - forces cancel (F_net = 0) rotational - torques cancel (torque_net= 0)

Answer 121

path taken (in contrast to "normal work" where direction doesnt matter, as its scalar

Answer 122

incompressible, neglible viscosity (syrup is very viscous), flow is laminar (aka flows smoothly), flow rate is steady

Answer 123

modulus is greater for glass - the lower the modulus the more it stretches

Answer 124

repel each other

Answer 125

attract each other

Answer 126

E+ then Q+ E- then Q-

Answer 127

positve test charge

Answer 128

pair of equal but opposite charges

Answer 129

scalar - no direction. This helps us understand it in relation to energy, work, and speed.

Answer 130

c/s or A (amp)

Answer 131

a potential difference

Answer 132

emf (electromotive force)

Answer 133

V=IR Resistance is constant, voltage is varried, current reverses direction if polarity of voltage is reversed

Answer 134

![]() Direcrion direcion of current is toward negative terminal. It is the direction positive charge carriers would flow (even though what is actually happening is electrons are drifing towards higher potential (+) ![]()

Answer 135

intensity of the other two stays the same. total current decreases. power supplied by battery will decrease. battery will last longer

Answer 136

C = E₀ A/d E_o is fundamental constant of nature, permittivity of free space =8.85x 10^-12 F/m This measures the capacitator's plates capacity of holding charge at a certain voltage

Answer 137

To create a uniform electric field, and to store electircal PE

Answer 138

V=Ed explains that electric field b/w capacitance plates is same at every point E is electric field

Answer 139

C=KE₀ A/d K is dialectric constant. In a vacuum, this =1.

Answer 140

Q remains the same - charge cannot change if not connected to battery. C increases - therefore V decreases (Q=CV) E (electric field) decreases (V=Ed PE decreases by factor of K (PE = 1/2QV)

Answer 141

E-E_induced = E/K Remember, K is dialectric constant C=KE₀ A/d C increases by factor of K Q increases by factor of K V stays the same E stays the same (V=ED) PE increases by factor of K (PE = 1/2 QV)

Answer 142

Dielectric polarizes molecules, creating induced charge on surface of the plates, creating a new electric field (E induced) in the opposite direction of the dielectric, leads to a decreaes in total electric field

Answer 143

rms is root mean square, means average. V_max/ς2 (Vrms equals max voltage over square root of two)

Answer 144

I_max/ς2 max current over square root of two

Answer 145

Moving electric charges

Answer 146

exerts force on charge that is moving through the field, but not on a charge at rest

Answer 147

out of the page into the page

Answer 148

NO. KE is constant. they cannot change speed of a particle, only direction of a particle.

Answer 149

if q is positive use RH if q is negative, use LF Thumb points i direction of velocity, fingers in direction of B. direction of F_B will be perpendicular to palm

Answer 150

out of the page inside the loop and into the page outside the loop

Answer 151

into the page inside the loop and out of the page outisde the loop

Answer 152

Almost uniform and is proportional the current and to the number of turns per unit length (N/L)

Answer 153

The greater K is, the stronger the spring is

Answer 154

The force the spring provides because it is always trying to get back to equilibrium

Answer 155

Hertz (Hz) cycles/sercond

Answer 156

f= 1/T f=1/(2π)ς(k/m) f= 1/(2π)ς(g/l) last one is for pendulums

Answer 157

T= 1/ T = 2π ς(m/k) T= 2π ς(l/g) last one is for pendulums

Answer 158

![]() First: L=1(1/2§) §=2L/1 Second: L=2(1/2§) §=2L/2 Third: 3(1/2§) §=2L/3 Therefore, §=2L/n (n is the harmonic #) § is wavelength

Answer 159

f_n=(n/2L)v n is 1,2,3, etc

Answer 160

longitudinal, direction the medium particles oscillate is parllel to the direction the wave travels.

Answer 161

medium's resistnace to compression and density

Answer 162

the faster sound travels

Answer 163

the slower sound travels

Answer 164

Enegy the sound wave transmits per second (power) per unit area w/m² w is waatts

Answer 165

decibels! dB or bel (B)

Answer 166

B = 10log₁₀(I/I₀) If I is multiplied by 10, add 10 to B If I is divided by 10, subtract 10 from B Ex: If I is multiplied by 10,000, add 10+10+10+10=40 to B

Answer 167

3 x10 ⁸ m/s

Answer 168

ROYGBV Red has lowest frequency therefore longest wavelength Violet has highest frequency, therefore shortest wavelength

Answer 169

c = fς | (fequency \* wavelenth)

Answer 170

at the same speed

Answer 171

E=hf=h c/ς h is plank's constnt, will be given on mcat

Answer 172

The angle of reflection is equal to the angle of incidence (see notes to draw)

Answer 173

Bending as light hits water (or some other medium)

Answer 174

When incident ray is perpendiuclar to the surface

Answer 175

How fast light travels through a medium

Answer 176

n = c/v speed of light in vacuum/speed of light in medium

Answer 177

n₁sinØ₁=n₂sinØ₂ If n2 \> n1, then the ray will bend toward the normal if n2

Answer 178

what happens when a light ray travels from a medium of high refractive index into one of lower, and if the ray's angle of incidence exceeds the criticle one

Answer 179

when light travels through a material, different frequencies have different speeds (this is why we have diff. colors). Diff colors have different refractie indexes - different angles of refraction

Answer 180

center of curvature

Answer 181

virtual images

Answer 182

real: light rays actually focus @position of the image and can b eprojected on a surface virtual, light rays dont actually focus on apparant location of the image, cannot be projected

Answer 183

more light greater power

Answer 184

Power. P = I²R So current is the biggest factor in the brightness of a lightbulb. The current will go towards path of least resistance, so if it has low resistance, it has stronger current, more power, and brighter lightbulb

Answer 185

U = k q₁q₂/r = U = 1/2qV ## Footnote (charge \* voltage)

Answer 186

changing direction of particle. It cannot change the magnitude of its velocity

Answer 187

R = mv/qB R is radius, v is velocity, q charge, B magnetic field, m mass

Answer 188

I (current) voltage

Answer 189

Evenly distributed on the surface

Answer 190

P = 1/2 qV

Answer 191

Destructive

Answer 192

decrease. they would move closer together