https://teddyrookbook.com/physics/physical-science/Recent content in Physical Science on Teddy Rook Bookhttps://teddyrookbook.com/img/share.jpghttps://teddyrookbook.com/img/share.jpgHugoenhttps://teddyrookbook.com/physics/physical-science/speed/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/speed/Average speed is total distance divided by total time: s = d/t. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/distance-time-graphs/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/distance-time-graphs/A steeper line means faster; a flat line means stopped. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/distance-displacement/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/distance-displacement/Distance is how far you traveled; displacement is how far and which way you ended up from the start. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/velocity/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/velocity/Velocity tells how fast and which way, so turning around changes it even at the same speed. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/acceleration-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/acceleration-intro/Acceleration is how quickly velocity changes: a = Δv/Δt, in meters per second per second. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/speed-time-graphs/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/speed-time-graphs/On a speed-time graph a rising line means speeding up and a flat line means steady speed. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/forces-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/forces-intro/A force is a push or pull between two objects, measured in newtons. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/net-force/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/net-force/Add forces along a line, counting direction, to find the net force. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/first-law-inertia/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/first-law-inertia/With zero net force, an object keeps the velocity it has, whether still or moving. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/second-law-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/second-law-intro/Net force equals mass times acceleration, so the same push speeds up a heavy cart less. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/mass-weight/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/mass-weight/Mass is the amount of matter; weight is the pull of gravity on it: W = mg, with g = 9.8 N/kg on Earth. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/friction-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/friction-intro/Friction acts where surfaces touch, against their sliding, and grows when they press together harder. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/third-law-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/third-law-intro/Forces come in pairs: when A pushes B, B pushes A just as hard in the opposite direction. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/momentum-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/momentum-intro/Momentum is mass times velocity, and in a collision the total momentum stays the same. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/collision-time/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/collision-time/Stretching a collision over more time lowers the force, which is how airbags, helmets and crumple zones work. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/gravity-mass-distance/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/gravity-mass-distance/Every two masses attract; more mass means more pull, and twice the distance means a quarter of the pull. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/pressure/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/pressure/Pressure is force spread over an area: P = F/A, in pascals (newtons per square meter). Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/energy-forms/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/energy-forms/Energy shows up as motion, height, stretch, heat, light, sound, chemical and electric energy. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/kinetic-energy/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/kinetic-energy/KE = ½mv², so doubling the speed gives four times the energy. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/potential-energy/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/potential-energy/Lifting an object stores energy: PE = mgh, measured from a chosen level. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/energy-conservation-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/energy-conservation-intro/As an object falls or swings, energy moves between kinetic and potential, and the total stays the same. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/work-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/work-intro/Work is force times the distance moved along the force: W = Fd, in joules. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/power-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/power-intro/Power is how fast energy is transferred: P = W/t, in watts. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/efficiency/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/efficiency/Efficiency is useful energy out divided by energy in, and it is always less than 100%. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/simple-machines/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/simple-machines/Ramps, levers and pulleys trade a smaller force for a longer distance. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/levers/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/levers/A lever balances when force times distance from the pivot is the same on both sides. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/heat-transfer/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/heat-transfer/Heat moves by contact, by moving fluids and by light, including infrared you can't see. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/phase-changes/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/phase-changes/Melting and boiling take in energy without raising the temperature; freezing and condensing give it back. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/wave-parts/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/wave-parts/Amplitude, wavelength, frequency and period describe a wave; the period is 1 divided by the frequency. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/wave-speed/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/wave-speed/Wave speed equals frequency times wavelength. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/wave-types/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/wave-types/In a transverse wave the medium moves across the wave's path; in a longitudinal wave it moves back and forth along it. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/sound/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/sound/Pitch comes from frequency and loudness from amplitude, and sound needs a medium to travel. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/echoes/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/echoes/Time an echo to find a distance: d = vt/2, because the sound goes there and back. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/wave-behavior/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/wave-behavior/When a wave meets a new material it can bounce off, be absorbed or pass through. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/em-spectrum/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/em-spectrum/Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays are all light, with different wavelengths. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/color/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/color/White light holds all colors, and objects look colored by the light they reflect. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/refraction-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/refraction-intro/Light bends when it changes speed at a boundary at an angle, and lenses use this to focus. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/radiation-energy/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/radiation-energy/Light comes in tiny packets whose energy rises with frequency, so one ultraviolet or X-ray packet can break molecules in cells and one radio packet can't. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/digital-signals/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/digital-signals/A digital signal sends information as separate values (0s and 1s), which can still be read exactly after some noise is added. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/charges-in-atoms/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/charges-in-atoms/Protons are positive and electrons negative; objects become charged by gaining or losing electrons, while the protons stay put. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/static-forces/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/static-forces/Like charges repel and unlike charges attract, more strongly when they are closer. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/fields-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/fields-intro/Gravity, electric and magnetic forces act across space through fields around objects. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/current-voltage/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/current-voltage/Current is the flow of charge, in amperes; voltage is the push given to each charge, in volts. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/circuits-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/circuits-intro/Charge flows only around a closed loop, and a switch opens or closes the loop. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/ohms-law/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/ohms-law/Voltage equals current times resistance: V = IR. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/series-parallel-intro/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/series-parallel-intro/In series one current flows through everything; in parallel each branch gets the full voltage. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/electric-power/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/electric-power/P = VI, and the energy used is power times time, often in kilowatt-hours. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/magnets/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/magnets/Every magnet has a north and a south pole, and its field lines run from north to south outside it. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/electromagnets/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/electromagnets/An electric current makes a magnetic field; a coil around iron makes it much stronger. Physical Science · Physics Ladderhttps://teddyrookbook.com/physics/physical-science/generators/Mon, 01 Jan 0001 00:00:00 +0000https://teddyrookbook.com/physics/physical-science/generators/Moving a magnet near a coil makes a current, so generators turn motion into electricity. Physical Science · Physics Ladder