How does a rocket propel in space if there is nothing to push it against?
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One of the basic principles of physics (Newton's Third Law) is that for every action (force) there is an opposite and equal reaction (force). The principle of a rocket motor may be understood by considering the example of a closed container filled with a compressed gas. Within this container the gas exerts equal pressure on every point of its walls. If a hole is punched in the bottom of the container, however, the gas at the bottom escapes and the pressure against the top of the container is no longer equalized. The internal gas pressure then pushes the container upwards in reaction to the jet of air escaping downwards. The amount of thrust developed by a rocket motor depends mainly on two factors, the velocity with which the burning gases leave the combustion chamber, and the mass of the burning gases.
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For the first case A marble on a (perfectly) flat surface, will remain in that state until energy of some kind is added.\n\nFor the second case to be as close to perfect conditions you would need to have a moving object out in deep space away from other bodies, because gravity will always be an effect, and in space to avoid the friction of the air.\n\nBut in simple terms the same marble on the flat surface give a push will move until external forces stop it, friction from the air and from contact with the surface.
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Rocket Principles\nA consquence of Newton's laws of motion is that for any object, or collection of objects, forces which only involve those objects and nothing else ("internal forces") cannot shift the center of gravity. For example, an astronaut floating in a space suit cannot shift his position without involving something else, e. g. pushing against his spacecraft. The center of gravity--or "center of mass"--is a fixed point, which cannot be moved without outside help (turning around it, however, is possible).\n\nBy throwing a heavy tool in one direction, the astronaut could get moving in the opposite direction, though the common center of gravity of the two would always stay the same. Given a bottle of compressed oxygen, the same result follows from squirting out a blast of gas (a scene that appeared in an early science fiction film). A rocket does much the same, except that the cold gas is replaced by the much faster jet of glowing gas produced by the burning of suitable fuel. At present, rockets are the only means capable of achieving the altitude and velocity necessary to put a payload into orbit.\n\nA rocket engine is a machine that develops thrust by the rapid expulsion of matter. Most rockets today operate with either solid or liquid propellants. The word propellant does not mean simply fuel, as you might think; it means both fuel and oxidizer. The fuel is the chemical rockets burn but, for burning to take place, an oxidizer (oxygen) must be present. Jet engines draw oxygen into their engines from the surrounding air. Rockets do not have the luxury that jet planes have; they must carry oxygen with them into space, where there is no air.\n\nThere are a number of terms used to describe the power generated by a rocket. \n\n\nThrust is the force generated, measured in pounds or kilograms. Thrust generated by the first stage must be greater than the weight of the complete launch vehicle while standing on the launch pad in order to get it moving. Once moving upward, thrust must continue to be generated to accelerate the launch vehicle against the force of the Earth's gravity. To place a satellite into orbit around the Earth, thrust must continue until the minimum altitude and orbital velocity have been attained or the launch vehicle will fall back to the Earth. Minimum altitude is rarely desirable, therefore thrust must continue to be generated to gain additional orbital altitude.\n\nThe impulse, sometimes called total impulse, is the product of thrust and the effective firing duration. A shoulder fired rocket has an average thrust of 600 lbs and a firing duration of 0.2 seconds for an impulse of 120 lb-sec. The Saturn V rocket, used during the Apollo program, not only generated much more thrust but also for a much longer time. It had an impulse of 1.15 billion lb-sec.\n\nThe efficiency of a rocket engine is measured by its specific impulse (Isp). Specific impulse is defined as the thrust divided by the mass of propellant consumed per second. The result is expressed in seconds. The specific impulse can be thought of as the number of seconds that one pound of propellant will produce one pound of thrust. If thrust is expressed in pounds, a specific impulse of 300 seconds is considered good. Higher values are better. A rocket's mass ratio is defined as the total mass at lift-off divided by the mass remaining after all the propellant has been consumed. A high mass ratio means that more propellant is pushing less launch vehicle and payload mass, resulting in higher velocity. A high mass ratio is necessary to achieve the high velocities needed to put a payload into orbit.\n\nThere are three categories of chemical propellants for rocket engines: liquid propellant, solid propellant, and hybrid propellant. The propellant for a chemical rocket engine usually consists of a fuel and an oxidizer. Sometimes a catalyst is added to enhance the chemical reaction between the fuel and the oxidizer. Each catego
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All 3 of Newtons laws of motion apply to a rocket, no matter the environment. Actually, All the laws of physics apply to a rcoket no matter the environment...it is not as if just on law controls how something opperates.\n\nNewton's 3 Law as well as the law of conservation of momentum work well to describe how a rocket engine accelerates a rocket.  These two laws apply both in an atmosphere and in space.
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A space craft is a vehicle that travels once in space. A   rocket is just a big, hot engine that is used to propel the space craft outside of Earth's gravitational pull. \n\nGood Luck!
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Normally you can't fire a bullet in space. Theres no air to burn with the powder.\n\nAssuming you do though, theres nothing to slow the bullet down, it would travel the same speed as it did on earth, and actually further as there is no friction or gravity to slow it down.
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Well, the different between air and helium on the weight of the balloon is marginal, so you would expect little or no observable distance. \n\nBut in principle its not as simple as is being made out here. Think for a moment about what keeps a ball up and what brings it down. Its hit into the air at first, and then a combination of gravity and air resistance bring it down. \n\nIn a vacuum the trajectory would depend only on initial velocity, because kinetic energy and potential energy both depend linearly on mass (so it cancels). In air the air resistance is proportional to square of the speed and size but not mass.\n\nNow, about that kick. Does it give 1) constant energy independent of the mass of the ball, 2) constant speed to the ball independent of its mass \n\nIf 1) then the heavier ball will be slower when kicked, so will not go as far\n\nIf 2) then the distance will be the same in vacuum as above but the larger ball will have more energy and so will take longer to slow by drag - it will go further
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Rockets carry two components -- fuel to burn and their own oxidizer to enable that in the near-vacuum of space.  In the case of liquid fuels, the two components must be stored separately.  Some solid rocket propellants have the fuel and oxidizer mixed together.
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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.
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If you disregard air resistance, both land at the same time.\n\nThe Earth's gravitational pull affects everything equally.
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I can't understand your question but, nothing moves with the aid of gravity, rather, things stop moving because of other forces acting upon them, e.g. drag, friction, etc. In space, there is no gravity (or much much less than on earth), which is why if you set a ball in motion in space, it would theoretically keep going forever, unless something got in it's way.
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Nothing in space.  It's weightless.
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As others have said, it's all about speed. \n\nIt's a minor point really, but it's a common misconception that it is the friction with the air that causes objects hitting the Earth's atmosphere at high speed to heat up. Actually it's not friction. The heating up is caused by the fact that the air in front of the object cannot get out of the way fast enough, so it's gets compressed in front of the object. As the air gets compressed the pressure rises and as the pressure rises so does the temperature. This is what causes the burning up effect.\n\nWhen a space craft is blasting off into orbit, as its speed rises it's also gaining altitude. At higher altitudes the atmosphere is less dense, so this compression of the air in front of the space craft never becomes a problem.\n\nIf a space craft used its rockets to slow its decent back to Earth then it wouldn't have any problems with burning up on re-entry. The reason they don't do this is because of the weight of the fuel that would be needed to do it. With current technology, no spacecraft could carry that amount of fuel and still be able to get into orbit.
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Aircrafts' wings gives the aircraft lift (i.e. shaped so that when wind passes through, it will be pushed up), and once a certain velocity is reached, the upwards lift is enough to counteract the forces of gravity (and exceed it), and thus they fly.\n\nSpaceships achieves escape velocity to escape from the Earth's gravitation (or at least far enough for the space ship to reach orbit). Then, at the orbit, it orbits earth at a certain velocity which gives it enough velocity to counteract the remaining attraction from Earth's gravity, hence it stays in space.
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This problem relies on Newton's second law: F=ma\n\na. This question is not completely specified.  The mass of the rocket is then (F/a=m or 2.0E7/a).\n\nb. We first find the net force on the rocket and use the mass from the previous question. Now we compute the acceleration at liftoff (F/m=a or (25E6 - 2.0E7)/(2.0E7/a)).\n\nc. We derive a new formula by double integration on acceleration. \nintegrate(a dt) = at, integrate(at dt) = .5at^2. The sequence gives us acceleration -> speed -> displacement at time t. The rocket will be at velocity: +(25E6 - 2.0E7)/(2.0E7/a)(7*60) m/s and at displacement of: +.5((25E6 - 2.0E7)/(2.0E7/a))(7*60)^2 m.
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First of all, there is no fixed end to the atmosphere: it gradually fades away to the density of interplanetary space.  However, the effective "top" of the atmosphere is often taken to be 60 miles (100 km), the altitude at which a (typical) unpowered satellite could make one orbit before air drag slowed it and caused it to fall.\nTo reach this altitude only requires that an object be headed upward, no matter how slowly.  To move upward requires that the object have some force propeling it which is at least slightly greater than the force of gravity pulling it down.  This force of gravity lessens with altitude, which is why a rocket needs a lot of power to take off, but little to maneuver in orbit.  Thus there is no minimum speed needed to reach the "top" of the atmosphere.\nHowever, the orbital velocity needed to stay in orbit is that velocity which just equals the downward pull of gravity, so orbital speed depends on the altitude of the satellite: it goes down with altitude.  (For example, at a typical low-orbit altitude of a couple hundred miles or so, the speed is around 17,000 miles per hour and the orbital period for one orbit is around an hour and a half; the Moon, 238,000 miles away, moves about 2000 mph and takes 28 days to orbit once. For mathematical details, see references on Kepler's Laws.
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No energy is required. Following Newtons first law of motion, a body (such as the Earth) will continue moving until a resultant force causes it to stop. In space there is no atmosphere, so the Earth just keeps flying around.