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If a photon rocket begins its journey in low earth orbit, then one year of thrusting may be required to achieve an earth escape velocity of 11. 2 km / s if the vehicle is already in orbit at a velocity of 9, 100 m / s, and 400 m / s additional velocity is obtained from the east to west rotation of the earth.
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If and photon
If it is " observed " ( measured with a photon ) not at a particular slit but rather at the screen, then there is no " which path " information as part of the interaction, so the electron's " observed " position on the screen is determined strictly by its probability function.
If the photon energy is too low, the electron is unable to escape the material.
If the photon energy is absorbed, some of the energy liberates the electron from the atom, and the rest contributes to the electron's kinetic energy as a free particle.
If an atom is already in the excited state, it may be perturbed by the passage of a photon that has a frequency ν < sub > 21 </ sub > corresponding to the energy gap ΔE of the excited state to ground state transition.
If a photon moves from one place and time – in shorthand, A – to another place and time – shorthand, B – the associated quantity is written in Feynman's shorthand as P ( A to B ).
If a light source (' the atom ') is in the excited state with energy, it may spontaneously decay to a lower lying level ( e. g., the ground state ) with energy, releasing the difference in energy between the two states as a photon.
If the atom is in the excited state, it may decay into the lower state by the process of spontaneous emission, releasing the difference in energies between the two states as a photon.
If we were to set 80 % of the mass of the photon rocket
If the signal data are not constant, then can be calculated from data where the signal is zero or relatively constant .</ ref > Notice that such an alternative definition is only useful for variables that are always non-negative ( such as photon counts and luminance ).
If the scattered photon still has enough energy left, the process may be repeated.
If the photon is of lower energy, but still has sufficient energy ( in general a few eV to a few keV, corresponding to visible light through soft X-rays ), it can eject an electron from its host atom entirely ( a process known as the photoelectric effect ), instead of undergoing Compton scattering.
If, the equivalent photon mass must be.
If the final vibrational state of the molecule is more energetic than the initial state, then the emitted photon will be shifted to a lower frequency in order for the total energy of the system to remain balanced.
If the final vibrational state is less energetic than the initial state, then the emitted photon will be shifted to a higher frequency, and this is designated as an Anti-Stokes shift.
Prior to any measurements being made, the polarizations of the photons are indeterminate ; If a measurement is made on one of the photons using a two-channel polarizer aligned with the axes of the coordinate system, the photon assumes either horizontal or vertical polarization, with 50 % probability for each orientation, and the other two photons immediately assume the identical polarization.
If the atom, which is now in the excited state, emits a photon spontaneously, it will be kicked by the same amount of momentum but in a random direction.
If the photon is absorbed, no new direction is given, and tracing for that photon ends.
If the photon reflects, the surface's bidirectional reflectance distribution function is used to determine the ratio of reflected radiance.
If an excited atom then emits a photon spontaneously, it will be accelerated.
If a wave containing exactly one photon passes over some atoms, and one of them absorbs it, that atom needs to tell the others that they can't absorb the photon anymore.
If an observer runs away from a photon in the direction it travels from a source, having it catch up with the observer, then when the photon catches up it will be seen as having less energy than it had at the source.
If and rocket
If the rocket or aircraft is moving at about a constant speed, then distance divided by time is just speed, so power is thrust times speed:
If a rocket is launched to deliver a payload from a planetary surface into space it is called a launch vehicle.
After being chosen to be the first teacher in space, McAuliffe was a guest on several television programs, including Good Morning America ; the CBS Morning News ; the Today Show ; and The Tonight Show Starring Johnny Carson, where, when asked about the mission, she stated, " If you ’ re offered a seat on a rocket ship, don ’ t ask what seat.
If done by direct propulsion, the rocket equation dictates that a large fraction of the spacecraft mass must be fuel.
If even more speed is needed than available from gravity assist alone, the most economical way to utilize a rocket burn is to do it near the periapsis ( closest approach ).
If the rocket does not launch within the " window ", it has to wait for the next window.
If the manoeuvre from GTO to GEO is to be performed with a single impulse, as with a single solid rocket motor, apogee must occur at an equatorial crossing.
If all went well the rocket would reroute the fuel for this engine to the other engines and have the rocket burn longer to compensate for the loss of acceleration.
If the cycle happens to match a resonance frequency of the rocket then dangerous oscillations can occur through positive feedback, which can in extreme cases tear the vehicle apart.
If the rocket is never lit then SpaceShipOne can glide down to the ground.
If aerodynamic drag and transient changes in pressure are neglected, a closed-form approximation for the peak height of a rocket fired vertically can be expressed as follows:
If the centre of mass is placed forward of the fins, the rocket will nose dive.
If the force is too much, no metal will hold it and the ship will blow up, so imposing a strict limit on how fast a rocket can accelerate ) and people using oxygen pills to survive unprotected in the vacuum of space ( which would suck their blood out through their skin and the air from their lungs as well as popping their eyes ), Space Patrol was better up on science.
If the rocket failed during the first phases of the flight, the Emergency Detection System ( EDS ) would automatically give the command to abort.
* Pad abort: If the rocket failed in the last five minutes before launch, the CM and the launch escape system ( LES, see figure ) would separate from the remainder of the rocket below with the LES propelling itself and the CM beneath it upward and eastward to the sea using a small solid-fuelled engine ( the pitch control motor ) at the top of the tower on the launch escape system.
If a rocket exceeds these capabilities ( or if it has a person on-board ), it is considered licensable.
If he does not contact them by that time, then they can launch the rocket.
If a stable or circular orbit is needed, once the payload reaches the highest part of its trajectory then an on-board rocket engine (" kick motor ") or other means is needed to circularize the trajectory to the appropriate Earth orbit.
If any of the worldlines bends away from a geodesic path in some region, we can think of the observers as test particles that accelerate by using ideal rocket engines with a thrust equal to the magnitude of their acceleration vector.
If and begins
If any official operation abroad begins to go wrong, we shall look to the ambassador to find out why and to get suggestions for remedial action.
`` If you saw the drama called Rhinoceros '', I said, `` think of the effect it would have on an audience of rhinos when the actor on stage suddenly begins turning into a rhinoceros.
If death receives more than its share of attention from the theologian and if sin receives less than its share, the gift of the life eternal through Christ begins to look like the divinely appointed means of rescue from temporal, i.e., created, existence.
If he begins to run too soon, the pitcher may throw to a base rather than to home — in this case, the runner is picked off, and will most likely be tagged out.
If a fighter is knocked down during the fight, determined by whether the boxer touches the canvas floor of the ring with any part of their body other than the feet as a result of the opponent's punch and not a slip, as determined by the referee, the referee begins counting until the fighter returns to his or her feet and can continue.
If the cord is twisted up tightly on itself and then the bucket is released, it begins to spin rapidly, not only with respect to the experimenter, but also in relation to the water it contains.
If more than one player remains after the first round, the " draw " phase begins.
If drain-to-source voltage is increased further, the pinch-off point of the channel begins to move away from the drain towards the source.
If a ship's hull classification symbol begins with " W ", it is a ship of the United States Coast Guard.
If a ship's hull classification symbol begins with " T -", it is part of the Military Sealift Command, has a primarily civilian crew, and is a United States Naval Ship ( USNS ) in non-commissioned service — as opposed to a commissioned United States Ship ( USS ).
If an appropriate form of written text is made available before formal schooling begins, reading should be learned inductively, emerge naturally, and with no significant negative consequences.
If an inability to sufficiently adjust to life circumstances begins within three months of a particular event or situation, and ends within six months after the stressor stops or is eliminated, it may instead be classed as an adjustment disorder.
If the carbonyl is at position 1 ( that is, n or m is zero ), the molecule begins with an formyl group H ( C = O )-, and is technically an aldehyde.
If the nation state begins to disappear, it may well be the direct or indirect result of globalization and internationalism.
" If he replies with the word " Accepto ", his reign begins at that instant, not at the inauguration ceremony several days afterward.
If met with ideal conditions on a new planet's surfaces, the bacteria become active and the process of evolution begins.
If the opponent in the hold begins to tap out at the same time a referee counts to three for pinning the opponent delivering the hold, both opponents have legally achieved scoring conditions simultaneously.
If a burial occurs on Chol HaMoed, shiva begins before is completed.
If they become plugged by debris, water begins flowing over the outside, depositing more calcite and creating the more familiar cone-shaped stalactite.
If the wedding is part of a religious service, then technically the service begins after the arrival of the participants, commonly with a prayer, blessing, or ritual greeting.
# If the word begins with ' KN ', ' GN ', ' PN ', ' AE ', ' WR ', drop the first letter.
If any contestants are visually impaired, the host will read the question and four choices all at once, then repeat the choices after the music begins.
; Loop-invariant code motion: If a quantity is computed inside a loop during every iteration, and its value is the same for each iteration, it can vastly improve efficiency to hoist it outside the loop and compute its value just once before the loop begins.
If a small external magnetic field is applied to the superconducting loop, a screening current,, begins circulating in the loop that generates a magnetic field canceling the applied external flux.
1.377 seconds.