Flashcards
Physics 112
Cards in this deck (26)
- 1positon as a function of time for an object moving with constant acceleration.Velocity as a function of position for an object moving with constant acceleration.
- 2equations Vx=v1x+at (only used if t known) X=X1+v1xt+1/2at^2 (Gives X if t known)Vx^2=V1x^2+2ax(X-X1)
N{gives Vx if X is known} - 3Newtons 1st law: an object at rest will stay at rest and an object in motion stay in motion with the same speed and direction unless acted upon by an unbalanced forceFriction = pulling force
(constant speed)
Friction < Pulling speed
(acceleration) - 4Newton's 2nd. Law: the vector sum of all forces acting on an object equals the objects mass times its acceleration.ΣF= m.a
ΣFx= m.ax
ΣFy= m.ay - 5Newton's 3rd. law: For every action, there is an equal and opposite reaction.F a on b = -F b on a
- 6work: when an object goes along displacement S along a straight line, while constant force F in the direction of displacement is applied to it.the work done by force is
W= F.S
unite Jouls - 7Average power: when a quantity of work Δw is done, during a time internal Δt, the average power or work per unit time is defined as Pav = ΔW/Δt unit = watt (w) = Jouls /s (J/s)Pav= F. Vav
P = F . Vinsta
1 hours power(hp)=746 Watt - 8circular motion: at any point the direction of acceleration is always to the center.even if the velocity is constant there is an acceleration because the velocity changes its direction which means acceleration.
- 9Newtons law of gravitation: every particle of matter in the universe attracts every other particle with a force that is directly propotional to the product of the mass of the particle and inversely proportional to the square of the distance between them.Fg=G (m1.m2)/r2
m1= mass of the first object
m2= mass of the second object
r2= Distance between the two objects
G is constant = 6.674x10-11 N.m2/K.g - 10Momentum: It is the product of the mass (m) by the velocity V P=mVTotal momentum: the sum of the momenta (plural of moment) of the object
P=Pn+Pb+Pc+…. - 11Conversion of momentum: the total momentum of a system is constant whenever the vector sum of the external forces on the system is zero.i.e the total momentum of an isolated system is constant.
- 12the colliding objects stick together and move as one object after the collision.Ma (Vai,x)+Mb(Vbi,x)=(Ma+Mb)(Vf,x)
- 13Definition of impulse: when a constant force F acts on an object the impulse of the force is defined by J is the force multiplied by the time internal during which it acts .J=F.(tf-ti)=F.Δt
Relationship of the impulse to change in momentum
J=ΔP = F.Δt = F.(tf-ti) - 14Center of mass: Postion Xcm= (ma.Xa)+(mb.Xb)+.../ma+mb+.. Ycm= (ma.ya)+(mb.yb)+.../ma+mb+..Center of mass for velocity
Vcm= (ma.Va)+(mb.Vb)+.../ma+mb+.. - 15Amplitude: is the maximum magnitude at the displacement from equilibriumCycle: is one complete round trip.
i.e A to -A back to A - 16Periode (T): is the time for one whole cycle. Unite is second T=1/fFrequency (f): is the number of cycles in one second
Unit Hertz (Hz)
f=1/T - 17Angular frequency (w): is the 2π times the frequencyw= 2.π.f
w= 2.π.1/T
Unit Rad/Sec - 18Energy in simple hormonic motion: E=1/2 m.Vx^2 + 1/2 K.X^2 =constantVx=+-√(k/m).( √(A^2 )-x^2
K: Spring constant
m: Mass of the object
A: Maximum displacement
X: The position of the object - 19Frequency of a simple hormonic motion in the terms of mass and spring constant: f=1/2π .√(k/m)period of a simple hormonic motion in the terms of mass and spring constant:
T=1/f=2π .√(m/k) - 20The simple Pendulum: Frequency f=1/2π .√(g/L) L= Length of the robSimple pendulum:
Periodic time
T=1/f=2π .√(L/g) - 21Transverse wave: the movement of the particle are perpendicular to the direction of the speed of the waveV= λf = λ/T
V: speed of the wave (m/s)
λ: Wave length (m)
T: period (sec.)
Speed of the transverse wave in a rope:
v= √Ft/M
Ft: tension of the rope (N)
M: mass per meter of the rope (Kg/m) - 22Fundamental frequency of the vibrating string: f1= 1/2L√Ft/M Ft: String Tention (N) M: mass per meter (kg/m) L: length of the stringOther frequencies:
fn=nf1
fn=n λ/2L
λn=2L/n - 23Density: if the mass m of material has volume v, its density is ρ=m/v (kg/m^3)Pressure:
the pressure P on a plane surface area of A is
P=F/A
(N/m^2)=Pa{pascal}
F: is the vertical force exerted on that surface. - 24Pascal's law: pressure applied to an enclosed fluid is transmitted to every portion of the fluid and the walls of the container- Pressure depends only on the depth.
- the shape of the container does not matter.
P=F1/A1=F2/A2=…1
From 1
F1=A1/A2.F2 - 25Continuty equation: Δv/Δt=A1V1=A2V2 Δv=change in volume Δt=change in time Δv/Δt=Flow rate (m^3/s) A1=tube cross section area V1,2= Speed of the fluid at cross section Less cross section area less velocity.Bernoulli's equation:
it relates pressure, flow speed and hight in a fluid.
P1+ρgy1+1/2ρV1^2=P2+ρgy2+1/2ρV2^2
P= pressure at point 1
ρ= fluid density
y= hight of the fluid at point
V= speed flow of the fluid at point - 26Statics: Moment/torque: moment= distance X vertical force on the distanceNote: if the moment direction is counter clockwise it is considered positive
if it is clockwise it is considered negative.