The Magnetic Field Due to a Solenoid
attracting and repelling each other in accordance with the law, 'Like poles repel, unlike poles attract'. The field at the centre of the solenoid is given by the equation where is the number of turns per unit length.
https://astarmathsandphysics.com/ib-physics-notes/electromagnetism/1288-the-magnetic-field-due-to-a-solenoid.htmlAristarchus and Copernicus
the second century BC, it was later promoted by Copernicus in thesixteenth century. The model placed the Sun at the centre of thesolar system, and relegated the Earth to be just one of the planetsorbiting the Sun, with all the orbits supposed to be...
https://astarmathsandphysics.com/ib-physics-notes/the-history-and-development-of-physics/1301-aristarchus-and-copernicus.htmlDe Broglie and Matter Waves
that label the position of the particle. The waves that constitute the wavepacket interfere constructively towards the centre of the wavepacket but less so towards the edge, and exhibit complete destructive interference outside the wavepacket. Wave...
https://astarmathsandphysics.com/ib-physics-notes/the-history-and-development-of-physics/1305-de-broglie-and-matter-waves.htmlOersted's Observations on the Magnetic Effects of Electric Current
were separate phenomena, magnetism only existing in the form of iron magnets, one of which was thought to exist at the centre of the Earth, producing the Earth's magnetic field. A professor at Copenhagen University, he was one day performing...
https://astarmathsandphysics.com/ib-physics-notes/the-history-and-development-of-physics/1319-oersted-s-observations-on-the-magnetic-effects-of-electric-current.htmlThe Ancient View of Ptolemy
Aristotle pushed the geocentric model of the Universe, with the Earth at the centre, and the Universe or Heavens revolving around it. Each of the Heavenly bodies – Sun, moon and planets – were attached to different sized, concentric perfect spheres...
https://astarmathsandphysics.com/ib-physics-notes/the-history-and-development-of-physics/1324-the-ancient-view-of-ptolemy.htmlPlotting Graphs, Axes and Lines of Best Fit
is added (or even a curve). The line (or curve) should not just join the dots. If it is a line it should go through the centre of the points, with as many points below the line as above, if possible and should be drawn with a ruler. If it is a curve it...
https://astarmathsandphysics.com/ib-physics-notes/measurements-units-uncertainty-and-principles/1343-plotting-graphs-axes-and-lines-of-best-fit.htmlDifferent Types of Force
thought of as friction. Tension When a string is stretched, a tension is produced in the string, always acting towards the centre of the string. When the string is attached to an object it will exert a force on the object equal to the tension....
https://astarmathsandphysics.com/ib-physics-notes/mechanics/1357-different-types-of-force.htmlGravitational Potential
not apply inside in Earth. Inside the Earth, we consider only that mass inside the sphere defined by the distance from the centre. The expression is more general however. Once you have the potential at one point, say and at some other point, say the...
https://astarmathsandphysics.com/ib-physics-notes/mechanics/1370-gravitational-potential.htmlThe Approximate Expression for the Gravitational Potential Energy
is is small compared to the radius of the Earth. The graph of gravitational potential against the distance from the Earth's centre is shown below. To move from a distance say, near to the Earth's surface to a distance we need to put in an amount of...
https://astarmathsandphysics.com/ib-physics-notes/mechanics/1378-the-approximate-expression-for-the-gravitational-potential-energy.htmlWeightlessness
his normal weight (below left). If the lift accelerates upwards with acceleration he experiences his weight doubling (above centre). If the cable holding the lift breaks, ignoring air resistance, the lift and the man in it would accelerate down with an...
https://astarmathsandphysics.com/ib-physics-notes/mechanics/1384-weightlessness.htmlThe Mass Spectrometer
of the particle always, so forces the particle to move in a circle. The centripetal force – the force acting towards the centre of the circle – is Equating the magnetic to the centripetal force gives Rearrangement of this gives If the ions have the same...
https://astarmathsandphysics.com/ib-physics-notes/quantum-and-nuclear-physics/1432-the-mass-spectrometer.htmlThe Photoelectric Effect - Finding Planck's Constant
The photons of light on the left and have enough energy to eject a photon from the metal plate, but the photon in the centre does not. The equation governing the photoelectric effect is (1) where is the maximum kinetic energy of the emitted electrons...
https://astarmathsandphysics.com/ib-physics-notes/quantum-and-nuclear-physics/1434-the-photoelectric-effect-finding-planck-s-constant.htmlArea of Circles Filling a Sector
\rightarrow r= \frac{10}{3} cm\] . The smaller circles extend out to \[10-2r=10- 2 \frac{10}{3}=\frac{10}{3} cm \] from the centre. Repeating the above process for the next largest circle gives us a radius for this circle of \[\frac{1}{3} \frac{10}{3} =...
https://astarmathsandphysics.com/ib-maths-notes/trigonometry/5001-area-of-circles-filling-a-sector.htmlInterference
constructive interference. The resulting wave is larger than either wave. If the waves are out of phase everywhere (below centre) then they have the same wavelength and we have destructive interference. The resulting wave has zero displacement...
https://astarmathsandphysics.com/ib-physics-notes/waves-and-oscillations/1490-interference.htmlJupiters Great Red Spot
is increasing, possibly as a result of shrinking. At the edge of the spot the wind speed is up to 430 km/h, but at the centre the wind speeds are close to zero. Infrared data indicates that the spot is colder and about 8 km higher altitude than most of...
https://astarmathsandphysics.com/university-physics-notes/planetary-science/1507-jupiters-great-red-spot.htmlSunspots
Sun's interior decreases; and with it surface temperature. A sunspot is actually a depression in the Sun's surface. At the centre is the dark umbra, where the magnetic field is radially out from the Sun, and surrounding is the lighter penumbra where the...
https://astarmathsandphysics.com/university-physics-notes/astronomy/1509-sunspots.htmlUsing the Biot - Savart Law to Find the Magnetic Field on the Axis of a Circular Loop
and hat r is the unit vector in the direction of For the point on the axis of the current loop above and Hence When at the centre of the coil,
https://astarmathsandphysics.com/university-physics-notes/electricity-and-magnetism/1554-using-the-biot-savart-law-to-find-the-magnetic-field-on-the-axis-of-a-circular-loop.htmlThe Basics of Simple Harmonic Motion
Simple harmonic motion occurs when motion in a circle with uniform acceleration is projected on a line through the centre of the circle. The motion is most naturally projected onto the x and y axes. Suppose the motion is projected onto the – axis. Then...
https://astarmathsandphysics.com/a-level-maths-notes/m3/3629-the-basics-of-simple-harmonic-motion.htmlElastic Strings
stored in a stretched spring by integration. Because we may also write Tension is a string is always directed towards the centre of the string, and has the same magnitude at each point of the string. If the string is fixed at one end to a surface with...
https://astarmathsandphysics.com/a-level-maths-notes/m3/3639-elastic-strings.htmlLamina Suspended at Angle to Horizontal
of a side from a vertex and the other at a vertex, so that the topmost side AB is at an angle to the horizontal. The centre of gravity O is two thirds of the distance from A to the midpoint of the side BC, and and the line from A to the midpoint of BC...
https://astarmathsandphysics.com/a-level-maths-notes/m3/3640-lamina-suspended-at-angle-to-horizontal.html