How would a astronaut return to their ship in space (Physics)?
405486
yes, if u throw any object away from u , u will be propelled in the opp direction by a velocity, v= mu / ( M + m ) where u is the velocity of the thrown object, m is mass of object and M is ur mass.\n\nthis is conservation of linear momentum for u!!
369838
Nothing really would happen.\nThe side of the astronaut facing the sun would be extremely hot, the side facing away from the sun would be very cold, probably even frozen.\nThe astronaut's body would be hit by small bits of flying rock and space dust.
1010543
Suppose you are taking a space walk near the space shuttle, and your safety line breaks. How would you get back to the shuttle? The thing to do would be to take one of the tools from your tool belt and throw it is hard as you can directly away from the shuttle. Then, with the help of Newton's second and third laws, you will accelerate back towards the shuttle. As you throw the tool, you push against it, causing it to accelerate. At the same time, by Newton's third law, the tool is pushing back against you in the opposite direction, which causes you to accelerate back towards the shuttle, as desired. This is the principle behind jet propulsion: a jet rocket expels fuel rapidly by ``pushing against it''. By the third law the fuel exerts an equal and opposite force against the rocket so the rocket accelerates in the opposite direction that the expelled fuel goes. Another example of the 3rd law is a book lying on a table. If the table were not there the book would fall under the force of gravity between the book and the earth. Why then doesn't the book move off the table, in accordance with the 2nd law? The table is exerting a force on the book that is just enough to cancel the gravitational force on the book. By Newton's third law, the book is also exerting an equal and opposite force on the table, and this is why the table feels the weight of the book. If the book were very heavy, its weight would cause the table to bend, or even break. This is illustrated in the following figure. \n\nThe answer to this question comes from the third law. Imagine the skateboard again. On the ground, the only part air plays in the motions of the rider and the skateboard is to slow them down. Moving through the air causes friction, or as scientists call it, drag. The surrounding air impedes the action-reaction. \n\nAs a result rockets actually work better in space than they do in air. As the exhaust gas leaves the rocket engine it must push away the surrounding air; this uses up some of the energy of the rocket. In space, the exhaust gases can escape freely.
461537
Before launch, the shuttle crew activates the the ship's rockets. At t=0, the Solid Rocket Boosters or SRBs are activated to provide the initial lift. As the name implies, the SRBs run on solid fuel in order to maximize thrust, but the design has a major drawback. Combustion of the solid fuel cannot be controlled in any way, and it will continue to burn the rest of the way until the fuel runs out 5 minutes later. So, the ship is stabilized before ignition.  After 5 minutes, the SRBs are jettisoned to lessen weight and the SRBs parachute back to earth. The shuttle continues on with the fuel in the external tank (the orange cone) attatched to its belly until the fuel it contains is used up 30 minutes later. That is then it is also jettisoned, but unlike the SRBs, the external tanks remain in space, for good. The shuttle then maneuvers itself around using its own fuel and thrusters to do the job it came up for. It may dock with the ISS, do some repairs, release its sattelite cargo or do whatever it came up to do.\n\nWhen it's time to head home, the shuttle again uses its thrusters and boosters to maneuver itself into low orbit and heads into the atmosphere for re-entry. As the shuttle heads deeper into Earth's atmosphere, friction between the shuttle and the air increases. The space shuttle is purposely built to utilize this effect for re-entry. Its design incorporates a flat base on the underside. That part and some others are generously covered with special ceramic tiles that can withstand temperatures up to 5000 degrees, depending on the thickness. So, the shuttle maximizes friction during re-entry by facing its underside to the direction it is travelling to, using the red-hot ceramic tiles to absorb the heat while slowing itself down. It is a dangerous procedure. If only one of the tiles cracked, went loose or dropped, the shuttle will disintegrate like shuttle Columbia. If the shuttle survives, it heads to its planned destination - a commercial runway. It slowly shifts its flying position back to aircraft-style and lands using landing gears and brake parachute.
1011585
One that would travel the spaceways, from planet to planet
945516
I'm not sure there is enough information in the question to answer it.  We need to know the altitude of the astronaut when he is accelerating.  The answer implies that the astronaut is at sea level (see the other answer, where the user adds 9.81, or the sea-level gravitational acceleration).  However, if the astronaut is in space, then the acceleration due to earth's gravity is reduced significantly.\n\nSo in showing your work, I'd recommend at least stating the assumption that the astronaut is at sea level.
368139
If the object has onboard power, then the speed is not really relevant to whether it will leave the atmosphere, just when. If you just fire an object upwards and it has no self-propulsion, however, then you need to calculate the change in gravitational potential energy (find out how far the atmosphere extends) and add the energy lost to air friction (this depends on velocity). Equate this to the object's initial kinetic energy and solve for initial velocity v. Your initial velocity will have to be larger than this.
262383
It requires enough thrust to escape Earth's Gravity. \n\nIt is said that a spacecraft uses more than 70% of the fuel on board in the first 20 minutes of the mission just to be able to "enter space", i.e. escape Earth's powerful gravitational pull.
1047344
Solar Sails.\n\nA spacecraft would deploy a huge sail to capture the solar 'wind', the constant stream of solar particles. A rather slow but economical method to move beyond Earth....
1159975
No.  I think it can be generalized that humans judge motion in two ways.  First, a physical reaction; feeling a car on the road, or wind in your face.  Second, a visual reference; such as trees buzzing past or a familiar landmark getting closer.\n\nSince there is no "atmosphere" to speak of in orbit (at least not what we'd consider an atmosphere anyway), there is nothing physical to oppose his motion.  Therefore, from his perspective, he is just sitting there.  Also, since the shuttle that he's tethered to is also moving at the same speed, it doesn't appear to move either (unless of course the astronaut is moving toward, away from, or parallel to the ship somehow).  Regardless, with no frame of reference, there is no sensation of motion.\n\nWell, what about the Earth?  Surely that is a frame of reference.  Well, yes and no.  Sure, one could look at the rotating Earth below them and get some sense of how fast they were moving.  However, anyone who has taken a road trip and has been driving towards a mountain range (i.e. driving across Nebraska towards the Rockies) knows that something that far away and that large can fool the senses into believing that you've stopped.  Therefore, I would (and this is an opinion) discount the Earth as a frame of reference.
6491
11.3 Km/sec at earth's surface (7 miles/sec)\n\nNOTE that escape velocity is the speed with which you would throw an object so that it does not fall back to earth. Rockets for example have constant propulsion and therefore do not need to travel with escape velocity to go into space.
193718
this would all depend on the angle of the secant, the depth of it, and, of course, the velocity at which you would be traveling upon entering the opening.  In general, you would simply roll till you ran out of momentum.  gravity still pulls to the core.
730814
assuming that you could do it and you didnt die and all that, you would go through to the other side.  if you include air resistance, you wouldnt make it to the other side, you would accelarate until you reached the center of the earth or until you reached terminal velocity, then you would start slowing down after you passed the center.  you would then start falling back toward the center in the opposite direction, passing it again, you would oscillate back and forth like this, losing some distance from center on each pass, eventually you would come to rest at the center
918232
I like Dr. Greg's solution to disappearing, but let's look at it a bit further, shall we?\n\nAssume the average room is 20 ft X 20 ft.; so the max distance I'd need to whisk out and seemly just disappear would be the diagonal: about 28 ft.  So to travel that in "12.5 milliseconds," like Dr. Greg suggests, I'd need to average v = S/t = 28/12.5 X 10^-3 = 2.24 X 10^3 ft per sec while crossing the room and bugalooing out of there.  That's better than 1,500 mph (there is a reason they say he travels "faster than a speeding bullet").\n\nStarting from a standing stop, our intrepid hero would need to reach 3,000 mph to average that 1,500 because the average would be v = (v1 + v0)/2 = (3000 + 0)/2 = 1,500.  To reach that end velocity, he/she would need to accelerate at a = v/t = (3,000 X 5280)/(12.5 X 10^-3) = 1,267,000,000 ft/sec^2; where 1 mile = 5,280 ft.  This is almost 1.3 X 10^9 (that's billion) ft/sec^2\n\nAcceleration due to gravity at Earth's surface is g = 32.2 ft/sec^2; so Superboy is accelerating at n = a/g = (1.3 X 10^9)/32.2 = .04 X 10^9 = 40 X 10^6 g's.  In other words, he would be pulling 40 million g's during that escape from the room.  But, hey, he's a superlad; so he can take it.  But could you...?\n\nConsider the amount of energy the caped crusader expends while getting away in less than the blink of an eye.  J = Fd; where J is work in foot-lbs, F is force (ma) in pounds, and d = 28 ft, the distance the big S moves across the room.  Thus, we have J = Fd = m(ng) d = mg (n) d = W n d = 220 X 40 X 10^6 X 28 = 246,400 X 10^6 = 246 billion ft-pounds of energy or work.  W = mg = Superkid's weight (I'd judge about 220 lbs), n = the number of g's pulled while accelerating (a = ng) up to 3,000 mph.\n\n246 billion ft-pounds of energy (work) is equivalent to 80 tons of TNT; or 160,000 pounds of TNT going off in that room when the super dude splits in less than the blink of an eye. [See source.]\n\nIf I were you, I'd not wait for Clark to split...could be hazardous to your health.
832992
Show the logistics of building a space station. i.e. First you would have to get a few modules built, then stock the modules with what you would need to continue. Figure in you are only allow to carry a limited amount of weight every time the shuttle leaves Earth. What would you bring first, second, third, etc. Who would you need to have up there? A pilot of the shuttle, some mechanics, maybe a physician - when would you be able to add solar panels for power? You can make it as involved as you want to.
661933
The thrust of rocket engines are how ships are controlled in space.  Many of the forces that affect air ships (drag, lift, gravity) do not apply since you specified no air or gravity.\n\nTechnically, air ships don't go to space, so there's no real answer to this question.  Richard Branson's Space Ship One recently flew to the edge of space and then landed like a plane, but (as the name indicates) it was a space ship, not an air ship.\n\nAnd there are air and gravity in space.  Gravity holds galaxies, separated by millions of light years, together, so gravity will definitely act on space ships only 100 or 200 miles above the earth.  What causes weightlessness in orbit is not a lack of gravity, but free fall.  The atmoshere is very, very thin at the altitudes where satellites and the shuttle fly, but it is that thin air, causing frictional drag on satellites and the space station, that require constant reboosting to keep them in orbit.\n\nKey to effective flight and control is stabilization, so in addition to moving and turning a ship in space, thrusters also are used to keep it from spinning (reaction wheels also are used for this function).
265616
The two key elements in this question are that the speed of the spacecraft is constant, and that you are at rest relative to the spacecraft.  In this situation, you will observe the beam of light moving forward and hitting the object just the same as if you were sitting in your living room.  This is in accordance with Einstein's Special Theory of Relativity.\n\nHowever, if the spacecraft were accelerating instead of moving at a constant speed, the same might not be true. As long as the spacecraft continues to accelerate, even at speeds below the speed of light, it is possible to set up a scenario in which the spaceship stays ahead of the beam of light forever!  This is in accordance with Einstein's General Theory of Relativity, which considers the effects of acceleration and gravity on light.