Introductory Physics Homework Help Forum

Free introductory physics homework help step by step from qualified mentors. Algebra and calculus based general physics homework. High school and undergraduate level.

Threads

I am confused by the concept of space-time in special relativity

  • rgtr
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Virial Theorem for an expanding globular cluster

  • Barbequeman
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Why Doesn't the E*A Equation Work for Electric Flux in This Case?

  • bluesteels
  • · Replies 14 ·
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14

Calculate Crumple Zone Rigidty?

  • AJ22
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3

Quick question about which radius to use on Gauss' law problem

  • bluesteels
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3

Finding ##x_c(t=0)## for a system of coupled Masses & Springs

  • Redwaves
  • · Replies 16 ·
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16

Calculate Principal Inertias - Exercise Hint

  • fabiancillo
  • · Replies 5 ·
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5

Free body diagram for an inverted pendulum in the rolling sphere

  • GottfriedLenz
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9

How to find deceleration up incline

  • xwalsh
  • · Replies 2 ·
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2

Question on Einstein's opening passage of relativity

  • s__1000
  • · Replies 18 ·
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18

Initial acceleration problem: Two children on a frictionless floor

  • Davidmb19
  • · Replies 7 ·
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7

Electric field due to a charged infinite conducting plate

  • vcsharp2003
  • · Replies 8 ·
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8

Ball rolling down a slope ending with a loop

  • Hendra
  • · Replies 12 ·
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12

Torque imposed by the Moon and Sun on the Earth given its precession

  • ago01
  • · Replies 6 ·
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6

Falling and sliding stick (David Morin)

  • Father_Ing
  • · Replies 33 ·
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Projectile Motion Experiment: Results Too High?

  • burakyildiz
  • · Replies 2 ·
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2

Spring compression -- Ball colliding with a spring-mounted platform

  • dge
  • · Replies 2 ·
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2

Why momentum of a ball bounced off a wall increases twice fold?

  • Eobardrush
  • · Replies 9 ·
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9

Propagating Uncertainties in acceleration when using a video software

  • Iwanttolearnphysics
  • · Replies 6 ·
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6

How Is the Second Leg of the Triangle Calculated in Vector Problem?

  • NormalForce1
  • · Replies 2 ·
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2

Gauss's Law for a sphere with a cavity, solving for E(r)

  • ThrawnGaming
  • · Replies 15 ·
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15

1D Elastic Collision between an Elephant and a Fly

  • ObitoLegend
  • · Replies 6 ·
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6

Ball on a string (vertical circle)

  • redlightgreen
  • · Replies 2 ·
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2

Find frequency such that two components have same average power

  • Tobias Holm
  • · Replies 4 ·
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4

Quartic function of a non-ideal spring

  • Semiclassical
  • · Replies 1 ·
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1

Where is the equilibrium point of a mass sliding down slacking cord?

  • yucheng
  • · Replies 15 ·
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15

Why bulbs and LED diodes keep glowing after being switched off?

  • pepediaz
  • · Replies 21 ·
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21

Magnitude of force acting on wedge and block

  • dl447342
  • · Replies 2 ·
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2

The Quantum Uncertainty of a Particle

  • maguss182
  • · Replies 13 ·
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13

To locate the centre of gravity of a rod

  • gnits
  • · Replies 5 ·
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5

RL circuit after switch has been opened

  • Ugnius
  • · Replies 6 ·
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6

Equivalent Capacitance and Resistance of this Circuit

  • goutes1234
  • · Replies 27 ·
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27

An introductory question about special relativity

  • Yink
  • · Replies 1 ·
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1

Newton's second law (My turtle named Newton being accelerated)

  • rgtr
  • · Replies 9 ·
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9

Is the Spring Launching Equation Correct?

  • physicsdude2
  • · Replies 6 ·
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6

Finding Spring Constant When Given Amplitude, Time, and Mass

  • physicsneedslabs
  • · Replies 9 ·
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9

Particles moving on a regular hexagon

  • Monsterboy
  • · Replies 12 ·
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12

How Does Torque Affect the Motion of a Disc Pulled Across a Table?

  • ago01
  • · Replies 3 ·
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3

To find the distance of a horizontally suspended rod from a ceiling

  • gnits
  • · Replies 2 ·
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2

Energy Efficiency Tips for Homeowners

  • tomcajot
  • · Replies 1 ·
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1

Electric force due to a moving charge

  • LCSphysicist
  • · Replies 7 ·
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7

Trajectory of a charged particle in the magnetic field (variable)

  • acrobaticelectron
  • · Replies 16 ·
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16

Equation calculations about the coefficient of kinetic friction

  • Javad
  • · Replies 5 ·
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5

Action Reaction Spring Scale Question

  • Ineedhelpwithphysics
  • · Replies 10 ·
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10

Wrong sign in my answer, why? SR + Addition of velocity....

  • LCSphysicist
  • · Replies 3 ·
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3

Help Me Solve This Khan Academy Question: Friction and Initial Velocity

  • Iwanttolearnphysics
  • · Replies 5 ·
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5

Is Throwing a Knife with No Spin Actually More Effective?

  • Aurelius120
  • · Replies 4 ·
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4

An object oscillating in simple harmonic motion

  • lorenz0
  • · Replies 6 ·
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6

Why Does a Wheel Move and How Does Torque Influence Its Dynamics?

  • erensatik
  • · Replies 12 ·
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12

Potential on each of these concentric spherical shells

  • vcsharp2003
  • · Replies 19 ·
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19

What is the Conservation of Energy in Spring Work at an Angle?

  • hayke101
  • · Replies 9 ·
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9

Trying to understand why I got this problem wrong

  • Bruh
  • · Replies 13 ·
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10

Vertical spring connected between two bodies with a rope above them

  • physics1000
  • · Replies 16 ·
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16

Confused about calculating the average energy from a distribution graph

  • ASKINGHUMAN
  • · Replies 2 ·
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2

Troubleshooting Interplanetary Cruise Calculations

  • Viii
  • · Replies 41 ·
2
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41

Accelerating pulleys (3 pulleys and 3 masses)

  • Yossi33
  • · Replies 5 ·
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5

Calculating work on an inclined plane

  • Diana Rico
  • · Replies 6 ·
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6

Calculating the Force of a Jump on the Moon

  • isaacwachsman
  • · Replies 10 ·
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Friction force on each foot and on each hand of a person

  • dl447342
  • · Replies 7 ·
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7

Is the Angular Velocity of Pinned Rods Calculated Correctly?

  • DrNG
  • · Replies 5 ·
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5

Charge density seen from a moving reference frame S' (SR + EM)

  • LCSphysicist
  • · Replies 1 ·
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1

Determining displacement and acceleration: A physics problem

  • kara123
  • · Replies 14 ·
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14

Potential energy, Wave function, Quantum physics

  • HektorHusky
  • · Replies 1 ·
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1

Determine the final train speed (mass and slinky on a train)

  • leafy
  • · Replies 13 ·
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13

Simple conceptual question about Ohm's law

  • engineeringstudnt
  • · Replies 15 ·
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15

Conservation of linear momentum, undergrad particle dynamics

  • greg_rack
  • · Replies 3 ·
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3

A fun, engaging and visual way of showing laminar flow for young kids

  • LT72884
  • · Replies 1 ·
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1

Finding Friction Force & Work with No Applied Force

  • kara123
  • · Replies 8 ·
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8

Relativity and Simultaneity: A Cosmic Perspective

  • martinlodge1964
  • · Replies 10 ·
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10

What Is the Rate of Change of Acceleration at t=2?

  • LT72884
  • · Replies 8 ·
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8

Uncertainty of pendulum period and pendulum length

  • dobbygenius
  • · Replies 7 ·
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7

Calculating the center of mass as an astronaut moves on a shuttle

  • ago01
  • · Replies 5 ·
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5

How Do You Find the Period of a Pendulum with a Length of 35 cm?

  • blueyedblonde
  • · Replies 3 ·
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3

Triangle problem from Feynman's exercises

  • czakun
  • · Replies 5 ·
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5
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3

Evaluate reflectance of an aluminum mirror

  • mcas
  • · Replies 5 ·
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5

About Work done when velocity is constant

  • Iwanttolearnphysics
  • · Replies 12 ·
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12

Net efficiency of a cascaded Carnot Engine and Fridge

  • baseballfan_ny
  • · Replies 1 ·
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1

Trajectory of an electron traveling near a current-carrying wire

  • alesdiazdeo
  • · Replies 4 ·
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4

Concept not understood -- Car tires pushing the car forward....

  • Ineedhelpwithphysics
  • · Replies 6 ·
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6

About KE and PE of a stone falling down a tube filled with oil

  • Iwanttolearnphysics
  • · Replies 10 ·
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10

Angular kinematic problem -- An accelerating merry-go-round

  • Nick tringali
  • · Replies 8 ·
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8

SHM Find amplitude from ω and x

  • dahoom102
  • · Replies 9 ·
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9

Calculating a star's density profile

  • Angela G
  • · Replies 3 ·
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3

Averaging the cube of semimajor axis to position ratio wrt to time

  • antythingyani
  • · Replies 9 ·
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9

To find the modulus of elasticity of a light elastic string

  • gnits
  • · Replies 7 ·
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7

How Does Mathematical Theory Explain Multiple Wave Reflections?

  • Redwaves
  • · Replies 8 ·
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8

Dsa -- Two masses orbiting their barycenter

  • antythingyani
  • · Replies 2 ·
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2

Finding the position of a middle charge to have Zero Net Force

  • sylent33
  • · Replies 9 ·
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9

Need help with this unequal length bifilar pendulum

  • dobbygenius
  • · Replies 21 ·
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21

Solving for Energy & Momentum in Physics Questions

  • anto
  • · Replies 2 ·
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2

Mass and spring on an inclined plane

  • Kenny555
  • · Replies 4 ·
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4

Calculate the angular velocity for each case

  • leafy
  • · Replies 5 ·
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5

Force between charged Ring and Rod, disproved Newtons 3rd law?

  • Hamiltonian
  • · Replies 3 ·
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3

Homework help : What object rotates at 90 RPM?

  • sayo
  • · Replies 3 ·
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3

Solving Equilibrium w/ Plank & Forces | Physics Problem

  • ago01
  • · Replies 7 ·
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7

Effect of Surface Area on the Drag Coefficient of a Parachute

  • pasta-lord
  • · Replies 6 ·
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6