Flashcards
Whats the unit?
Lenght
meter (m)
Whats the unit?
Mass
Kg
Whats the unit?
Force
N
Whats the unit?
Time
s
Whats the unit?
Work and Energy
J
Whats the unit?
Power
W
Give the prefix and abbreviation for each of the following powers:
10^9
Giga (G)
Give the prefix and abbreviation for each of the following powers:
10^6
Mega (M)
Give the prefix and abbreviation for each of the following powers:
10^3
Kilo (K)
Give the prefix and abbreviation for each of the following powers:
10^-2
Centi (c)
Give the prefix and abbreviation for each of the following powers:
10^-3
Milli (m)
Give the prefix and abbreviation for each of the following powers:
10^-6
Micro (µ)
Give the prefix and abbreviation for each of the following powers:
10^-9
Nano (n)
Give the prefix and abbreviation for each of the following powers:
10^-12
Pico (p)
what are the sin and cos values for the following angles?
0
sin: 0
cos: 1
what are the sin and cos values for the following angles?
90
sin: 1
cos: 0
what are the sin and cos values for the following angles?
30
sin: 1/2
cos: √3/2
what are the sin and cos values for the following angles?
60
sin: √3/2
cos: 1/2
what are the sin and cos values for the following angles?
45
sin: √2/2
cos: √2/2
what are the sin and cos values for the following angles?
180
sin: 0
cos: -1
what is the difference between a scalar quantity and a vector quality?
Scalar: magnitude but no direction
Vector: magnitude and direction
Scalar or vector?
Distance, speed and mass
scalars
Scalar or vector?
Displacement, Velocity and force
vectors
(T/F) The sum of two vectors is the resultant of the vectors
True
Formula:
Average acceleration
a= ∆v/∆t
Formula:
v=
V= Vo +at
Formula:
∆x=
∆z= Vot+ (at^2/2)= Vt= (Vo + v / 2)t
Formula:
V^2
V^2= Vo^2 +2a (X-Xo)
Formula:
V=
V= (Vo + v / 2)
Is weight a vector or scalar?
What is the formula for calculating weight?
vector
weight= mass x gravity
What are the Newton’s three laws of motion?
- A body in motion with constant velocity in a straight line path or at rest will remain that way unless an net force acts upon it.
- F=ma
- To every force there is always an equal and opposite force.
What are the formulas for the initial horizontal and vertical velocities of a projectile launched with speed v at and angle of ∅ to the horizontal?
horizontal: Vcos∅
Vertical: Vsin∅
what does the total horizontal distance,x, traveled by a projectile equal?
X= (initial horizontal velocity)(time in the air)
What is the formula for gravitational force? F=
F= G m1m2 / r^2
If the distance between two objects is doubled, by how much is the force of gravity increased or decreased?
decrease by a factor of 4
(T/F) A body in translational equilibrium has a net force moving it at a constant velocity.
False.
A body in translational equilibrium has no net force acting on it.
If a lever arm is halved, by how much does the torque increase or decrease?
decrease by half
what is the formula for torque?
T= r F sin ∅ (r: distance between force and axis rotation)
when calculating torque, which rotation direction is considered positive and which negative?
counterclock: +
clockwise: -
(T/F) For rotational equilibrium to occur, the sum of all torques acting on a body must be zero.
True
what is translational motion?
motion in which the position of the object’s center of mass changes as a function of time.
what is the formula for the force of static friction?
Fs ≤ µs N
what is the formula for the force of kinetic friction?
Fk = µk N
what is the formula for centripetal acceleration (for a body in uniform circular motion)? a=
a= (velocity)^2 / radius = v^2/r
(T/F) For a planet orbiting a star, the centripetal force is equal to the gravitational force.
true
what is the formula for work?
W= F d cos ∅
what is the unit of work?
Joule (N*m)
what is the formula for power?
P= W/t
what is the unit of power?
Watt (1 J/sec)
what are the units for KE?
Joules
What is the formula for gravitational potential energy? U=
U=mgh
what are the units of gravitational potential energy?
Joules
(T/F) The total mechanical energy of a body is the sum of its kinetic energy and potential energies.
True
Is the total mechanical energy a constant if the only forces that act on a body are conservative (E=K+U=Constant)
Yes
What is the change in energy of a system if only conservative forces act upon it?
If only conservative forces act on a body, then ∆E=0
What is the formula for momentum? p=
P=mv
what is the formula for impulse J? J=
J= Ft= MV-MVo=∆P
Is kinetic energy conserved in a completely elastic collision?
yes
(T/F) Net external force must be equal zero for conservation of momentum to occur.
true
What is the formula for the center of mass for two masses, m1 and m2, lying along the x-axis at points x1 and x2?
X= (m1x1 + m2x2) / (m1+m2)
(T/F) Momentum is not conserved in an inelastic collision.
False
What are the temperatures in Kelvin and Celsius for the following?
Absolute Zero.
0 K
-273 C
What are the temperatures in Kelvin and Celsius for the following?
Freezing point of water
273 K
0 C
What are the temperatures in Kelvin and Celsius for the following?
Boiling point of water
373 K
100 C
What is the formula for converting Kelvin to Celsius?
Tc= Tk-273
What is the formula for thermal expansion of a solid?
∆L=α L∆T
What is the formula for volume thermal expansion of a liquid or a solid?
∆V= ɞV∆T
What type of heat transfer involves the direct transfer of energy from molecule to molecule through molecular collisions?
Conduction
What type of heat transfer involves the transfer of energy by electromagnetic waves?
Radiation
What type of heat transfer involves the physical motion of heated material?
Convection.
what are the units of heat?
calorie, btu or Joule.
what is the difference between a calorie and Calorie?
Calorie is a nutritional term = 1000 calories
What is the formula relating heat gained and temp charge? Q=
Q=mc∆T
what is heat of fusion?
amount of energy required for a phase from solid to liquid
what is heat vaporization?
Heat vaporization is the amount of energy required for a phase change from liquid to gas
What is the formula for heat gained or lost during a phase change?
Q= mL
What is the SI unit of pressure?
Pascal
What is an isobaric process?
process done @ constant pressure
What is the formula for work (given an isobaric process?
W=P∆V
What is the formula for the first law of thermodynamics?
∆U= Heat energy gained- Work done by the system
(T/F) Heat flow out of system is (+) and heat flow into a system is (-)
False.
heat out system -
heat into system +
What is an adiabatic process?
one in which no heat flows from the system to its surroundings or vice versa
What is the second law of thermodynamics?
entropy of a closed system will either increase or remain unchanged.
Does a totally reversible process increase the entropy if the universe? what about an irreversible process?
totally reversible: does not increase entropy of the universe but an irreversible process does.
What is the equation for density?
p=m/v
What is the density of H2O?
1000kg/m^3 = 1g/cm^3
What is specific gravity?
ratio of a substances density to the density of water.
What is the formula for calculating pressure?
P= Force/Area
What is the formula for absolute pressure in a liquid?
P= Surface pressure + (p)(gravity)(depth)
= Po+ pgh
What is gauge pressure?
pressure in excess at atmospheric pressure
(T/F) Pascal’s principle states that a change in pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and to the walls of the container.
True
What is the relationship between the areas and forces when the system is in equilibrium?
(F1/A1)=(F2/A2)
(T/F) Both pistons move the same distance when a force is applied to one of them.
False
What is the formula for buoyant force?
FB=pgV
Given a pipe varying cross sections, how do fluid velocity and cross-sectional area relate throughout the pipe?
A1V1=A2V2
what is viscosity?
measure of the internal friction of a fluid.
Does viscosity of a liquid generally increase or decrease as temp rises?
an increase in temp generally causes the viscosity of a liquid to decrease.
What is the formula for Young’s Modulus?
Y= (F/A) / (∆L/L)
(T/F) Unlike charge attract and like charges repel.
True
What is the formula for Coulomb’s Law?
F= (Constant)(charge 1)(charge 2)/ distance^2
If the distance between two charged objects is tripled, by how much does the electrostatic force change?
decrease by factor of 9
If the distance between two charged objects is halved, by how much does the electrostatic force change?
increase by a factor of 4
What is the formula for an electric field at a distance(r) from a charge (q)?
E=K (q)/r^2
In which direction will an electric field vector point around a positive charge?
away
In which direction will an electric field vector point around a negative charge?
toward
What is the formula for the force that a charge (q) experiences in an electric field (E)?
F=qE
what are the units of an electric field?
(Newtons/Coulomb) or (Volts/meter)
what are the units of voltage?
Volts or Joules/Coulomb
what is the formula for electric potential given a charge (q) at a distance of (r)?
V=k (q/r)
What is the potential difference between two points on an equipotential line?
0
what is the formula for electrical potential energy?
U= qV
How much work is done on a charge if it is moved in a straight path between two equipotential points?
no net work is done.
what are the units of magnetic field?
Tesla.
Tesla = 10^4 Gauss
what is the formula for the force on a moving charged particle in a magnetic field?
F= qvBsin ∅
What force will a stationary charged particle in a magnetic field experience?
no force
What force will a moving charge experience if it travels parallel or antiparallel to a magnetic field?
no force
What are the units of current?
Amperes
1A= 1 Coulomb/sec
What is the formula for current?
I=∆q/∆t
What is the formula for the force on a current carrying wire in the presence of a magnetic field?
F= ILB sin ∅
A proton moving in a magnetic field experiences a force towards the top of the page. An electron moving in the same direction as the proton experiences a force in which direction?
Towards the bottom of the page
A proton moves towards the top of the page in a region where a magnetic field is directed into the page. What is the direction of the magnetic force?
Towards the left
A long straight wire carries a current directed towards the top of the page. What is the direction of the magnetic field on the left side of the wire?
The field points out of the page.
What is the formula for the magnetic field created by a long straight wire?
B= µo i/ 2 π r
A magnetic field is created by a loop of wire. What is the formula for the magnetic field at the center of the loop?
B= µo i/ 2r
(T/F) in DC current, the charge flows in one direction only.
True
(T/F) In AC current, the change flows in one direction only.
False.
The flow of charge changes direction periodically.
(T/F) By convention, the direction of current is the direction in which a negative change would flow.
False.
Direction of current is where the positive charge would flow.
What is the formula for Ohm’s law?
V=IR
How do the following affect the resistance of a conductor?
Increased length
as the length increases, the resistance increases.
How do the following affect the resistance of a conductor?
Increased cross-sectional area.
Cross-sectional area increases= resistance decreases.
How do the following affect the resistance of a conductor?
Increased temperature
Temp increase= resistance usually increases
How do the following affect the resistance of a conductor? Increase resistivity (ρ)
resistivity increases= resistance increases.
What is the formula for electrical power?
P=IV=I^2= V^2/R
What is the formula for calculating resistance given resistors in series?
Rs= R1 +R2..etc
What is the formula for calculating resistance given resistors in parallel?
1/Rp= 1/R1 +1/R2…etc
What is Kirchoff’s 2nd law?
The sum of the voltage drops around a circuit loop equals the sum of the voltage rises around the loop.
If a 7A of current flow into a three way junction and 3A leave via one of the routes, how much current leaves via the other?
7A- 3A = 4A
What is the formula for capacitance?
C=Q/V
What are the units of capacitance?
1 Farad = 1 Coulomb/Voltage
What is the formula for the electric field between the plates of a capacitor?
E= V/d
(T/F) As plate area increases, capacitance increases proportionally.
True
Does the introduction of a dielectric material between the plates of a capacitor increase or decrease the capacitance?
increases the capacitance.
What is the formula for calculating capacitance given capacitors in series?
1/Cs= 1/C1+ 1/C2…etc
What is the formula for calculating capacitance given capacitors in parallel?
Cp= C1+ C2..etc
For AC current, what us the formula for calculating Irms?
Irms= Imax/ √2
For AC current, what is the formula for calculating Vrms?
Vrms= Vmax/ √2
What is the formula for Hooke’s law?
F= -K x
What are the formulas for angular frequencies of a mass on a spring and of a pendulum (SHM)?
ω= √K/m [spring] ω= √g/L [pendulum]
What is the formula for kinetic energy (SHM)?
K= (1/2) mv^2
What is the formula for potential energy (SHM)?
U=(1/2)kx^2 [ spring]
U= mgh [pendulum]
(T/F) For an object in SHM, E=K+U= Constant.
True
When is an object’s kinetic energy greatest (SHM)?
at equilibrium point.
When is an object’s potential energy greatest (SHM)?
at maximum displacement from equilibrium
(T/F) For an object in SHM, frequency = 1/Period.
True
What are the formulas for the period of a mass on a spring and of a pendulum in SHM?
T= 2Π√m/k [spring] T= 2Π√L/g [pendulum]
Describe particle oscillation in a transverse wave.
particles oscillate perpendicular to wave motion in a transverse wave.
Describe particle oscillation in a longitudinal wave.
Particles oscillate along the direction of wave motion in a longitudinal wave.
What is the formula relating the speed of a wave to its frequency (f) and wavelength (λ)?
v=fλ
(T/F) A sinusoidal wave crosses its equilibrium point every 90°
False.
a sinusoidal wave crosses its equilibrium point every 180 °
(T/F) The fundamental harmonic has the longest wavelength and thus the smallest frequency of all the harmonics.
True
(T/F) The higher the harmonic, the greater the wavelength.
False.
The higher the harmonic= the shorter the wavelength
What is a node?
point in a standing wave that remains at rest.
What is an antinode?
point in a standing wave that fluctuates at max amplitude.
Two waves that are 180° out of phase exhibit which type f interference?
Destructive
Two waves that are 720° out of phase exhibit which type f interference?
Constructive
(T/F) When two waves are out of phase by 180° and interfere with each other, the resulting displacement is always zero.
False.
The resultant displacement is only zero when the two waves have equal amplitudes.
What is the formula for intensity?
I=(P/A)
I= (power/ area)
What is the beat frequency for two frequencies which differ by 4 Hz?
4Hz.
The beat frequency is equal to the difference of the two frequencies.
(T/F) The observed frequency from a source emitting a sound is higher if the source is moving toward a stationary observer.
True
(T/F) Standing waves in pipes open at both ends have nodes at the ends of the pipes.
False.
standing waves in pipes open at both ends have antinodes at the ends of the pipe.
(T/F) Standing waves in strings fixed at both ends have nodes at the ends of the strings.
true
(T/F) Higher harmonics of standing waves in open pipes have higher wave speed than lower harmonics.
False. The wave speed of all harmonics is the same.
What is the speed of an electromagnetic wave (light) in a vacuum?
3x 10 ^8 m/s
What type of image do plane mirrors create (real or virtual)?
virtual
How are focal length and radius of curvature related?
Focal length = radius of curvature /2 = r/2
What is the formula relating object distance, image distance and focal length?
1/f= 1/o+1/i=2/r
Does a virtual image have a positive or negative image distance?
negative
If an image is in front of a mirror, is it real or virtual?
real
Does a real image have a positive or negative image distance?
positive
whats the formula for magnification?
m=-i/o
(T/F) A negative magnification signifies an upright image.
False.
A negative magnification signifies an inverted image
A positive magnification signifies an upright image.
What type of image does a diverging (convex) mirror create?
A diverging mirror always creates a virtual upright image.
What type of image does a converging (concave) mirror create when the object is placed beyond the focal point?
real inverted image
What type of image does a converging (concave) mirror create when the object is placed inside the focal point?
virtual upright image
Does a convex mirror have a positive or negative focal length (or radius of curvature)?
negative
Does a concave mirror have a positive or negative focal length ( or radius of curvature)?
positive
What is the formula for index of refraction?
n= c/v
What is the formula for snell’s law?
n1 sin θ1 = n2 sin θ2
Under what conditions will light undergo total internal reflection?
internal reflection will occur when light travels from a medium with a higher index of refraction to a medium with a lower index of refraction and with an angle of incidence greater than the critical angle.
Does a converging lens have a positive or negative focal length?
positive
Does a diverging lens have a positive or negative focal length?
negative
(T/F) The “real” side of a lens is the side opposite that from which light originates
true
What type of image does a diverging lens produce?
virtual upright
(T/F) The electron Volt (eV) is a unit of energy.
True
What happens to an electron that absorbs a photon?
jump to higher energy level
what happens when an electron jumps from a higher energy level to a lower energy level (orbit)?
will emit a photon whose energy equals to the difference in energy between the two levels.
What is the minimum energy needed to ionize an electron in a state with energy -10 eV?
10 eV.
What is the threshold frequency (photoelectric effect)?
minimum frequency of light that will cause the emissions an electron.
(T/F) The excess energy of a photon is converted to extra kinetic energy of the emitted electron
true
What is the formula for calculating the kinetic energy of an emitted electron?
K- hf-W
W= h x fT
fT: threshold frequency
How many electrons will be emitted when using light with a frequency below the threshold frequency?
None.
Is the energy of a photon dependent on frequency or on amplitude?
frequency
What is the formula for calculating the energy of a photon?
E=hf
What is the photoelectric effect?
phenomenon whereby electrons are emitted by a metal that is exposed to light
(T/F) Photon energy increases when wavelength increases.
False.
Photon energy increases as wavelength increases.
(T/F) The splitting of white light in a prism is an example of dispersion.
True
What is diffraction?
spreading out of light as t passes through a narrow opening.
(T/F) Light waves can constructively and/or destructively interfere with each other.
True
What is polarized light?
light in which the electric fields of all the waves are oriented in the same direction.
what type of image does a converging (convex) lens create when the object is placed beyond the focal point?
real inverted
what type of image does a converging (convex) lens create when the object is placed inside the focal point?
virtual upright
What re the units of power for a lens?
diopters
What is the formula for calculating lens power?
P=1/f
