User Noumeno

39 votes

Why is acceleration directed inward when an object rotates in a circle?

answered Dec 13, 2020 at 15:19

30 votes

Why do we need instantaneous speed?

kinematics velocity speed calculus

answered Jan 3, 2021 at 14:21

23 votes

Does a rotating rod have both translational and rotational kinetic energy?

homework-and-exercises rotational-dynamics rotational-kinematics moment-of-inertia rigid-body-dynamics

answered Dec 9, 2020 at 18:02

21 votes

Why is angular momentum a vector?

angular-momentum rotational-dynamics vectors

answered Jun 10, 2021 at 14:52

10 votes

How does a satellite maintain circular orbit?

newtonian-mechanics forces newtonian-gravity orbital-motion satellites

answered Dec 16, 2020 at 14:17

7 votes

How does the second law of thermodynamics function when a system is at maximum entropy?

thermodynamics statistical-mechanics entropy

answered Jun 23, 2021 at 12:49

6 votes

Potential energy and force

forces classical-mechanics potential-energy conservative-field

answered Jun 15, 2021 at 9:29

6 votes

Why is the photon clock equivalent to all clocks?

special-relativity time time-dilation thought-experiment

answered Aug 3, 2020 at 13:00

5 votes

Does all EM radiation consist of photons?

electromagnetic-radiation visible-light photons

answered Jan 10, 2021 at 10:57

4 votes

Why did water not drip form this small bottle?

newtonian-mechanics fluid-dynamics fluid-statics free-body-diagram surface-tension

answered Dec 30, 2020 at 13:25

4 votes

Inertial and non-inertial frames in classical mechanics

classical-mechanics reference-frames

answered Dec 31, 2020 at 13:19

4 votes

Accepted

Do time dilation and length contraction cancel out?

special-relativity kinematics

answered Dec 13, 2020 at 13:11

4 votes

Why we add the individuals quantities to find the total amount of a system's "quantity"? Is this by definition of "total"?

classical-mechanics energy momentum vectors superposition

answered Jul 16, 2020 at 16:16

3 votes

Does electric field obey the triangle law of vector addition and subtraction?

electromagnetism electric-fields vectors vector-fields linear-systems

answered Sep 7, 2020 at 9:58

3 votes

Accepted

What is the cause of electric force?

forces electrostatics electric-fields coulombs-law

answered Dec 14, 2020 at 15:18

2 votes

What is the work done by gravitational force when you lift an object?

forces energy work

answered Dec 15, 2020 at 9:15

2 votes

Why can ropes pull but not push?

newtonian-mechanics forces free-body-diagram string

answered Dec 16, 2020 at 16:07

2 votes

What is the $y$-axis in an electromagnetic wave?

waves electromagnetic-radiation

answered May 21, 2021 at 9:22

2 votes

Accepted

Questions regarding particle spin

quantum-mechanics quantum-field-theory particle-physics quantum-spin

answered Mar 11, 2021 at 9:49

2 votes

How was it found that a charge produces an electric field rather than a 'local' electric force?

electrostatics

answered Jun 23, 2021 at 11:44

1 vote

How do electrical devices limit the current flow from a socket?

electric-circuits electric-current electrical-resistance voltage electrical-engineering

answered Jun 14, 2021 at 16:37

1 vote

Accepted

Relationship between voltage and distance in electrodynamics

electromagnetism electrostatics electric-circuits charge voltage

answered Jun 17, 2021 at 10:48

1 vote

Definition of a joule

newtonian-mechanics energy work si-units metrology

answered May 11, 2021 at 10:26

1 vote

Is my intuitive understanding of physical infinity correct?

cosmology spacetime universe

answered May 21, 2021 at 8:39

1 vote

Why the gravitational potential energy at infinity is zero?

newtonian-mechanics newtonian-gravity energy-conservation potential-energy conventions

answered Jun 3, 2021 at 15:26

1 vote

Do all impossible processes disobey certain conservation laws?

particle-physics conservation-laws standard-model

answered Jun 5, 2021 at 10:34

1 vote

Would there be any gravity inside a hollow planet made of a spherical shell of basalt crust?

newtonian-gravity symmetry planets

answered Dec 15, 2020 at 9:43

1 vote

Why does this block move backwards?

homework-and-exercises newtonian-mechanics forces free-body-diagram

answered Sep 7, 2020 at 10:18

1 vote

Integral of a dot product

electrostatics energy potential integration

answered Jul 3, 2020 at 9:20

1 vote

Accepted

Does electrostatic force act at the centre of mass of a body?

electromagnetism electrostatics electric-fields

answered Dec 14, 2020 at 10:39

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47 Answers

Why is acceleration directed inward when an object rotates in a circle?

Why do we need instantaneous speed?

Does a rotating rod have both translational and rotational kinetic energy?

Why is angular momentum a vector?

How does a satellite maintain circular orbit?

How does the second law of thermodynamics function when a system is at maximum entropy?

Potential energy and force

Why is the photon clock equivalent to all clocks?

Does all EM radiation consist of photons?

Why did water not drip form this small bottle?

Inertial and non-inertial frames in classical mechanics

Do time dilation and length contraction cancel out?

Why we add the individuals quantities to find the total amount of a system's "quantity"? Is this by definition of "total"?

Does electric field obey the triangle law of vector addition and subtraction?

What is the cause of electric force?

What is the work done by gravitational force when you lift an object?

Why can ropes pull but not push?

What is the $y$-axis in an electromagnetic wave?

Questions regarding particle spin

How was it found that a charge produces an electric field rather than a 'local' electric force?

How do electrical devices limit the current flow from a socket?

Relationship between voltage and distance in electrodynamics

Definition of a joule

Is my intuitive understanding of physical infinity correct?

Why the gravitational potential energy at infinity is zero?

Do all impossible processes disobey certain conservation laws?

Would there be any gravity inside a hollow planet made of a spherical shell of basalt crust?

Why does this block move backwards?

Integral of a dot product

Does electrostatic force act at the centre of mass of a body?