click below

click below

Normal Size Small Size show me how

# MCAT Physics 1

### Physics: Kinematics, Work & Energy, Newton's Law, Fluids

Question | Answer |
---|---|

1 eV | 1.60x10^-19J |

h | 6.626 x 10^-34 J*s |

Rh | 2.18x10^-18 J/e- |

c | 3.0x10^8m/s |

√2 | 1.4 |

√3 | 1.7 |

1 mole; ideal gas; STP | 22.4L |

1 mole | 6.022 x 10^23 particles |

SOH-CAH-TOA | 3-4-5 5-12-13 8-15-17 |

log(AB) | log A +logB |

log(A/B) | logA-logB |

log(A^B) | B*logA |

log(1/A) | -logA |

logx | ln(x)/2.3 |

log(n x 10^m) | m+0.n |

x^0 | 1 |

x^1 | x |

(x^a)(x^b) | x^(a+b) |

(x^a)/(x^b) | x^(a-b) |

(x^a)^b | x^(ab) |

(xy)^a | (x^a)(y^a) |

(x/y)^a | (x^a)/(y^a) |

x^(-1) | 1/x |

x^(1/n) | n√x |

x^(m/n) | n√(x^m)=(n√x)^m ex: x^(9/2)=√x^9=(√x)^9 |

Angle chart | Sin(0)=0 Sin(30=π/6)=1/2 Sin(45=π/4)=√2/2 sin(60=π/3)= √3/2 sin(90=π/2)=1 sin(180=π)=0 sin(270=3π/2)=-1 cos(0)=1 cos(30=π/6)=√3/2 cos(45=π/4)=√2/2 cos(60=π/3)= 1/2 cos(90=π/2)=0 cos(180=π)=-1 cos(270=3π/2)=0 |

vector | physical quantity w/both magnitude & direction |

scalar | physical quantity w/magnitude but no direction |

Vector adding & subtracting * when given angle use SOHCAHTOA to find vector X&Y components | Add: Head of 1st vector must meet tail of 2nd vector & draw arrow from tail of 1st to head of 2nd Subtract: place head of two vectors together & draw arrow from tail to tail For 3 or more: break into x&y components Y& Xtot=R=√(x^2tot +y^2tot) |

Linear Motion Eqns | (tax) ▲x=Vi*t + 1/2a*t^2 (vat) Vf=Vi + a*t (vax) (Vf)^2=(Vi)^2+2a*▲x Vavg=1/2(V+V1) X=v*t=((V+Vi)/2)T *Find max height Vel. vertical=o at highest point of path v=√(2gh) |

Center of mass | -point where single force can be applied in any direction & cause all points to accelerate equally -if uniformly dense it will consider with geometric center but if not it will shift to heavier side X=(m1x1+m2x2+..)/(m1+m2+..) |

Hooke Law (spring) | F=-k▲x yield point: deformed to point it can't gain it's original shape fracture point: deformed to breaking point |

Displacement vs time | slope=Vinstanteneous (v=▲d/t) upward slop=+ vel downward slope=- vel straight line=constant vel straight horizontal slope= m=0 v=0 curved line= m=changing v=changing |

velocity vs time | slope=a instanteneous (a=▲v/t) upward slop=+ a downward slope=- a straight line=constant a straight horizontal slope= a=0 curved line=a=changing (-) a could be slowing down or going in reverse direction |

Total displacement | (area above x-axis & below curve)-(area below x-axis&above curve) |

Total distance | sum of areas b/w curve & x-axis |

Types of Forces | Fnet=sum of all forces Fnet=o when equal in magnitude & opposite in direction Gravitational: mg Electromagnetic: require magnet/charge object Contact: Normal (Fn) & Friction (Fk or Fs) Univ Gravitation: GM1M2/r^2 |

Projectile Motion | Peak height found by v=√(2gh). to find max height of projectile launched from ground V=Visin(angle) due to vx=0 so final vel. can be found due projectile dropped from certain h |

How to draw free body diagram | 1) Draw it in simple terms 2)Find center of mass 3) Define system & draw only forces acting on system 4)know if Fnet exist or net |

First Law of Newton | (law of inertia) any object in a state of rest or motion stays in that state unless a force is applied |

Second Law of Newton | (F=ma) m↑a↓if F is constant but F↑a↑ if m=constant |

Third Law of Newton | (-Fa=Fb) for every action there's an equa; & opposite rxn |

Uniform circular motion | Fc=M(v^2)/r=ma a=(v^2)/r |

Universal Gravitation | F=GM1M2/r^2 (m*kg/s^2) G=6067x10^-11(m^3/kg*s^2) determines how quickly two objects w/slightly different masses accelerate toward each other |

Inclined Planes | Fn=mgcos(angle)=Fy Fx=mgsin(angle) Look at diagram |

Friction static | fs≤µkFn when surfaces don't slide |

Friction kinetic | fk=µkFn when surfaces slide |

Torque | =F*r*sinΘ r=distance b/w point of rotation & F is applied -could be CCW or CW ↑τ ↑rotation of accel ↑F ↑r -Fg always middle of all forces(stick has mass) -mboard found by picking midpoint as τboard & point of rotation no longer at end of board |

Equilibrium | Fnet=o τnet=0 so a=o v=constant static equi: velocities=0 dynamic equi: velocities=nonzero but constant Fup+Fnet=Fdown |

system | area separated from universe(surroundings) E leaving system=E entering surroundings E total system= systems sum |

open system | energy(work&heat) & mass exchanges w/surroundings |

closed system | energy (work&heat) are exchanged but not mass |

isolated system | energy (work &heat) & mass aren't exchanged |

Energy unit | Joule (J)=1kg*(m^2)/s^2=1N*m |

Mechanical energy | Etot=KE+U=1/2mv^2 + mgh or 1/2mv^2 -GM1M2/r |

Gravitational potential energy | -GM1M2/r=mgh E↓r↓ |

Elastic potential energy | 1/2k▲x^2 |

1st Law of Thermodynamics | ▲Etotal=W+q=KE+U+▲Einternal |

Work | W=F*d*sin(Θ)=-PV |

adiabatic | q=0 ▲U=W |

constant vol | W=0 ▲U=q |

Isothermal | ▲U=0 W=q |

2nd Law of Thermodynamics | process that moves from one state of equilibrium to another , entropy of system and environment together will increase or remain the same |

Linear expansion | -increase in length by most solids when heated ▲L=α*L*▲T T↑L↑ mnemonic: (αl▲t) |

volume expansion | increase in volume of fluid when heated ▲V=ß*V*▲T |

conduction | direct transfer of energy via molecular collisions (direct contact) |

convection | transfer of heat by the physical motion of fluid |

radiation | transfer of energy by electromagnetic waves |

specific heat (J,calories, Calories (kcal)) | q=mc▲T -only used when object doesn't change phase -NO TEMP change during phase change Q>0 heat gained Q<0 heat lost |

heat of transformation | Q=m*L -quantity of heat required to change the phase of 1g of a substance |

Work Kinetic Theorem (J, N*m) | -absence of heat; adiabatic U=q so W=▲KE W=F*d*cos(Θ)=-P▲V F is (+) when same direction as displacement F is (-) when in opposite direction W DONE on system it's (+) W DONE on surroundings (system doing work) it's (-) W>0 compression W<0 expansion |

Conservation of Energy | K1+U1=K2+U2 so ▲E=0 There are no non-conservative forces (kinetic frictional forces, pushing & pulling forces) |

Power (J/s) | P=W/▲t=▲E(tot)/t |

Instantaneous power | Pinst=F*v*cos(Θ) |

Fluid density (kg/m^3) | p=m/vol |

density of water | 1000kg/m^3=1g/cm^3 |

specific gravity | sg=p(substance)/p(water) sg<1 lighter than water sg=1 equilibrium as heavy as water sg>1 heavier than water |

Fluid pressure(N/m^2) | P=F/A -pressure experienced by the object as a result of the impulse of collisions |

Fluids at Rest | P=pgy p=density g=gravitational constant y=depth of fluid from the top of object to the bottom of fluid ↓y ↓mass ↓pressure P=F/A=m1g/A1=m2g/A2 |

Gauge pressure | Pg=P-Patm measure of the pressure (negative fluid/air sucked in) to atmosphere pressure |

Absolute pressure | P=pgy+Patm |

P total fluids | add each Pfluid when fluids are stacked one above the other |

Pascal's Principle | pressure applied distributed undiminished throughout that fluid Ex: air pressure on top of mountain is low due to atmosphere acting like sea of air where y↓ m↓ since closer to the top P=mgy↓ |

Hydraulic lift | W1=W2 since F1d1=F2d2 A2>A1 F2>F1 d1>d2 -look at slide |

Buoyancy Force | Fb= p(fluid)*V(fluid)*g=M(fluid)*g Vfluid dissipated=A*y -▲P,▲y,▲F reach MAXIMUM when object FULLY submerge and values DOESN"T change w/ depth once submerged |

Archimede's Principle | -Fb exerted by standing fluid on object submerged or sunk ↑P ↑F ↑y since P=pgy=F/A |

Floating object | (p(obj)/p(fluid))=(Vfluid/Vobj)≤1 Fb=Fg(object) Mfluid*g=Mobj*g M(fluid)=M(obj) |

Submerged object | (p obj/p fluid)=(V fluid/ V obj)=1 Mfluid=Mobj p fluid=p obj |

Sunk object | p obj/p fluid≥ 1 Fb + Fn=Fg=M obj * g Fb Fg M obj M fluid Vfluid=Vobj |

Weight Loss Apparent *sunk object | Fn< Fg p fluid/p obj *100=apparent weight loss |

Characteristics of Ideal Fluid | 1) No viscosity- tendency to resist flow 2) Incompressible- uniform density 3) Lack Turbulence- experience laminar (steady) flow so same velocity in same direction &magnitude 4) Experience irrotational flow- no rotation |

Volume vs Mass Flow Rate | Vol. Flow rate= Q=A*v ↑A↓v Mass Flow rate= I=p*Q=p*A*V |

Characteristics of Non-ideal Fluid | drag, real viscosity, turbulence, compressible ↑velocity in center of pipe ↑resistance flow ↑fluid-obj interface ↓width of pipe ↑drag ↑Length of pipe *Flow from high to low pressure ▲P=Q*R←resistance Q=(▲P*π*r^4)/8*R*L R→viscocity L→pipelength |

Bernoulli's Eqn | P1+ 1/2p*(V1)^2 + pgh1= P2+ 1/2p*(V2)^2 + pgh2 ↓ ↓ KE U h: measure from bottom to top *relationship b/w P&V: ↑stay put ↑stung ↑P but if not P↓(↓molecular collision) |