Introductory Physics Homework Help Forum

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Free introductory physics homework help step by step from qualified mentors. Algebra and calculus based general physics homework. High school and undergraduate level.
How to show 400 neutrinos are present?
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674
Change in apparent magnitude of a star after exploding
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3
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790
How do I correctly analyze the mass balance of a tractor seat?
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3
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691
Just looking for confirmation for a torque calculation
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3K
I solved few questions on kinematics -- Is my working correct?
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10
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7K
Tension Question for Ship Container and Wind Gust
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12
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1K
Pressure and temperature phase diagrams
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6
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743
Solving for Work Done When Accelerating a Mass
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3
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830
Question about springs and rotational/translational energy
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4
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2K
Question about Rutherford experiment: Which of these could not be concluded?
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12
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2K
Equilibrium problem: Multiple forces acting on this hinged, supported beam
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1K
Freefall chord through the Earth -- calculus proof
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2K
Find the coefficient of stiffness of this spring (with non-negligible mass)
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9
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845
Friction of a sliding mass on a slope
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4
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737
Is it possible to measure SQRT(2) kg with a scale?
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8
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648
Trying to understand the relationships between Forces, Mass and Inertia
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10
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979
What would the voltmeters measure?
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7
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650
Siren frequency heard by observer when an ambulance passes
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26
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1K
How to solve this kind of problem? (Mechanics Theory)
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16
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1K
Energy in simple harmonic motion--car problem
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4
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733
Why am I calculating the unknown mass of ice incorrectly?
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22
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1K
Question about absorption line spectra
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21
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1K
What does it mean that when light is reflected the "wavelengths of each contributing hue are subtracted"?
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16
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1K
Newton's 3rd Law of Motion: Is the Punching Bag punching back?
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4
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837
Oscillatory motion problem: Bicycle wheel rotation oscillation
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17
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1K
Pressure versus stress in uniformly charged sphere
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11
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1K
Doubts on Diodes -- Why is voltage shifted by 0.7V?
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7
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2K
Angular Momentum Conservation | Velocity at perigee
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8
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808
Circuit with time varying current
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10
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889
Determining the Change in Bulb Brightness by Changing Circuit
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6
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1K
What does the middle of a chain on a pulley mean?
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9
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839
Constant acceleration problem: Dog chasing a surprised cat
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13
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997
Two bars connected by a spring on a floor with friction
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2
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37
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2K
The derivative of the dot product "distributes" over each vector
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5
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732
Calculating the sum of displacement vectors
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5
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791
A problem about the laws of conservation: Bullet colliding with a wood block
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28
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1K
Force on a point charge near a uniformly charged rod
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3
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1K
Two rods with fixed angle, find the velocity of the crossing point
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1
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672
Stumped on mathematical proof
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13
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671
A 50 cubic foot tank contains saturated 134a at 100F and a quality of 50%
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11
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1K
How can "work" done by a force be negative?
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19
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1K
Torque that a grounded infinite sheet exerts on a dipole
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11
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1K
Two tanks are connected by a valve and line
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4
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901
Spring launcher firing steel balls
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2
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674
Circular motion question: Mass on a rod rotating in a vertical circle
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4
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948
Calculating Motor Force & Torque
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9
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892
Bead on a rod which is being pulled by an ideal string with velocity v
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27
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1K
Appliance plug connected wrongly: live neutral earth
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13
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767
Finding the direction of forces
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5
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702
Finding parallel or in-series resistors
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3
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743
Help needed on mass-energy equivalence
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7
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823
Momentum: instantaneous or average?
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1K
Derivation process of Selection Rule of hydrogenic atom
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562
A question about the perpendicular vector
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2
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566
Trouble understanding frames in relativity
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4
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877
Why does the PE of particles during steam condensation decrease?
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14
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1K
Torque on a sign hung by a hinge
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3
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673
Acceleration of a ball at its max height after being thrown upwards
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766
Oscillation of fluids in a U tube
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2K
A microwave oven of mass 13.0kg is pushed a distance 8.80m up a ramp
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2
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693
Free-body diagram: Spring-loaded cylinder sliding on a metal rod
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1K
A 2.8-kg block slides over the smooth icy hill -- Find the minimum speed to clear the pit
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795
A household fridge removes heat, determine power the fridge draws
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1K
Find h in the problem involving a stone thrown upwards
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621
Voltage-resistance graph for this circuit with a variable resistance
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4
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716
Work done by a balloon that is rising
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8
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828
Coefficient of friction of a sandwiched body
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15
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939
Kinematics, is this a poorly worded question?
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7
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884
Efficiency of Stirling Cycle - Is it the same as the Carnot Engine?
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14
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1K
Circular motion and moment of inertia - circle loop
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1K
Pressure question: Weight of a car calculated from tyre contact patch area
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3
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954
Ionic thruster high school science project
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2
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744
Rolling without Slipping Demo
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1K
RCL series circuit analysis: Damping Constant
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1
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736
Electric field of a charged disc with a small circle cut out of it
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9
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808
Block tied to a fixed string on an accelerating wedge
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2K
Use of imaginary charge vs Gauss' law
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12
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1K
Relation between the velocity vector and the acceleration vector of an object
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736
Issue deriving the third law of thermodynamics
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11
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1K
First Law of Thermo: Audience body heat warming a concert hall
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25
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1K
Rotational Dynamics problem with instantaneous frame of reference
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6
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760
Distribution of Energy when work is done on a system of 2 masses connected by a spring
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17
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2K
What Does -∂V/∂x Represent in Newton's Law?
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2K
How to approach this question using SUVAT equations?
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785
Confused about kinematic equations
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20
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2K
What is the relationship between tire size and pressure changes?
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13
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1K
Moment of Inertia of Solid Sphere - Proof
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6K
Reading of Ammeter for this circuit with Voltage Controlled Resistors
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1K
Relation between Friction, Velocity, and Acceleration
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Is this statement acceptable? (time derivative of a rotating vector)
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4
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725
Entropy Change For Van Der Waals Gas
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5
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635
Maximum Power dissipated at load resistor
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1K
Poiseuille law and friction force help
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630
Reversible, adiabatic expansion - Entropy Change
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5
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756
Linear momentum but quadratic kinetic energy?
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4
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549
Are there two downward forces acting on the pivot of the rotating rod?
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3
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Thermodynamics: Violating Clausius => Violating Kelvin
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10
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809
The motion of a skateboarder along and above a ramp
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2
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629
Deriving the particle's motion using numerical integration
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5
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737
Circular motion, coin on a rotating disk
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2
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807