can an object be increasing its speed as its acceleration decreases?
472797
The only time an object's speed will not be increasing or decreasing is when the acceleration equals zero.  When this is not true, the object is increasing or decreasing in speed.  As acceleration goes from positive to zero, the speed will begin to increase more slowly over time.\n\nAn example of this would be the speed of a car when approaching its maximum velocity.  The car will readily increase speed from 0 to 60, in say 8 seconds. As it approaches its top speed, say 115 MPH, it will do so more slowly as you get past 70 mph.  When the horsepower equals the power caused by wind drag, the acceleration will go to zero, the velocity will stop increasing, and the speed will be constant.
237074
Yes, but you notice the rubber ball is going slower now. Its because part of the momentum has been transfered from the ball to the sidewalk (eventually tranfered to the Earth itself).  This is called transfer of momentum.
1048247
There may be objects (tachyons) that move faster than light, up to perhaps infinite speeds.\nHowever, nothing already slower than light can accelerate to or beyond the speed of light.
609692
No. All motion is "Forward". Right down to the tiniest Particle. It can be pushed but not pulled. No matter the direction.
482492
So long as there is rate of change of motion
919955
Speed and Acceleration are related in that acceleration is the rate of change of your speed (should be velocity since you can take into account change in direction for accelerations).\n\nThe relationship can be mathematically expressed as:\ndv/dt = a.\n\nThat is, the change in velocity over the change in time.
118159
it increases its velocity if it has positive acceleration. In other words, if its velocity is in the same direction as its acceleration.
79621
yeah, mass increases. the lorentz factor is:\n1/sqrt(1-v^2/c^2)  where sqrt is square root, v is the velocity of the object, c is the speed of light, and ^2 means squared.  you would plug in the velicity you wish to find out about to v.  time decreases for you by this factor, mass increases, and length decreases.(ive had to derive these formulas from simple mechanics formulas; they're correct.) If you would plug in velocities to this formula, you would notice that the effect is negligable for any velocities not very very close to the speed of light.  Well, we definately can't go the speed of light because if you look at the formula, then v^2 would be equal to c^2 so v^2/C^2 would be 1, and 1-1 is 0. this would mean that the denominator would be 0 which is impossible.  we also can't go faster because then v^2/c^2 would be greater than one, thus subtracting that from one would yield a negative answer which would then be under a square root sign.  this is also impossible.  that's how we know we can't go as fast or faster than light speed.  Now, as far as how fast we can actually go, that depends a lot on biology.  as we get faster and faster, our mass increases and our length(and therefore volume) decreases.  now, the formula for density is m/V(mass over volume,) so our bodies would get more and more dense the faster we went. this is why there would be a limit and we couldn't just go so close to the speed of light so that time would slow down for us but not for everyone else, thus basically traveling forward in time. The question of how fast we can go becomes a question of how dense our bodies can become before either the pressure builds up too much in our cells, or our blood gets so dense it can't properly carry oxygen to our cells. The thing is, you really have to be very close to the speed of light to feel this effect.  the speed of light is 299792458 m/s. that's close to 300 million meters per second.  now lets say we go 200 million meters per second.  that's pretty darn fast, and i dont even know if we could go that fast due to the enormous amount of energy it would require to produce such accelerations.  but lets say we do.  plugging this into the formula, we get 1.16. we multiply this by the original mass, giving an increase in mass of only 16%. this isn't really all that much, we could probably handle that increase in mass, but i really don't know, my expertise is not in biology.  Still though, 200 million meters per second is pretty damn fast, anything much less than that would most certainly be negligable. you can try out some speeds for yourself to see what kind of effect it would have(you need a graphing or good scientific calculator otherwise it will round to 1 in certain places and you won't get any change at all.)  We won't have to worry about them coming anywhere close to speeds that affect our mass anytime soon though.
924224
No.  The design of the vehicle does not matter, it is the old e=mc^2.\n\nAs you accelerate, your vehicle gains mass, until, as you get closer to the speed of light, the mass gain approaches infinity, and it then takes an infinitely powerful push to overcome this infinite resistance.\n\nIn the case of the nested doll ships, if we use the external (larger ships), to begin the journey, you would find yourself in the strange position of continually needing greater power from ever smaller engines.
919057
It doesn't always speed up. Depends on the material. The less dense the quicker it will be able to go. More dense the slower it will go. The only way it could actually speed up is if it is passing through air directing into a vacuum (near zero particles). http://en.wikipedia.org/wiki/Light#Refraction
964035
You need to consider vectors ....\n\nAcceleration has a direction. In the case of gravity its down towards the ground. \n\nNow what accelerationis doing is changing the instantaneous velocity of the particle or object or whatever.\n\nVelocity is also a vector.\n\nSo if the velocity is in the opposite direction to the acceleration then the object will motion will slow down and eventually increase in the same direction as the acceleration.\n\nIf the velocity is in the same direction then it will increase in that direction.\n\n So if UP is defined as positive then down is defined as negative. This goes for:\n- position (above (+) and below (-) ground if ground level is defined as zero);\n- velocity is positive if the object is moving up and negaitve oif it is moving downward; and\n- acceleration is positive if applied upward or negative if applied downward.\n\nNote acceleration is in the same direction as an applied force as by Newton's Second Law, F = ma and mass is a scalar quantity .. it has no directionality. It is the same wherever the object is. (Not to be confused with weight which is a force attracting us to the ground and is dependent on the strength of gravity. So for example we weigh on earth and are weightless in space and are 1/6 of our weight on the moon etc ... In all locations our mass is the same but the forces acting on us are different)
93119
Force = mass x acceleration\n\nacceleration = force/mass.\n\nWith a given force, as mass increases, acceleration decreases.
354266
The farther the distance from the object (or ground), the slower you seem to be passing it.
392981
Is the speed at which it travels.
313900
Think of this\nwhen it comes to space the constant thing is the speed of light. Speed is the TIME it takes something to travel set distance.\nAt the moment we are moving through space. An hour ago we were a few hundred thousand miles from where we are now. If you were sitting still where we were a few hous ago, you would be slightly older than us.\nThis is because the constant thing in space is the speed of light. As we get closer to the speed of light either time gets smaller or distance gets smaller.\n\nIf this does not seem possible, just think of a unit of time as one vibration of an atom. Go faster, atoms vibrates slower, your time is therefore slower than some one who is still. (this is a metaphor people can comprehend, not quantum fact)\n\nSo question 1. Light is travelling at speed of light. Time and space do whatever they have to do to accomodate this.\n\nQ2 No, see Q1. You also would no be strong enough to throw the ball\n\nQ3. The closer one gets there first. just like anything else.\n\nQ4. What fuel? It would accelerate exponentially as the mass decreased. Top speed comes dowon to rates of accelerate, motor efficiency, drag, ect. Then as you got really fast your mass increases. Mass increases (again I'll use a compehendable metaphor and not quantum physics) because distance decreases, things are closer together, denser, heavier. Then your rate of fuel consumption would increase exponetially and your velocity would barely change. Then you'd run out of fuel
6524
Newton's second law:\nFirstly, this law states that if you do place a force on an object, it will accelerate, i.e., change its velocity, and it will change its velocity in the direction of the force.\nSecondly, this acceleration is directly proportional to the force. For example, if you are pushing on an object, causing it to accelerate, and then you push, say, three times harder, the acceleration will be three times greater.\nThirdly, this acceleration is inversely proportional to the mass of the object. For example, if you are pushing equally on two objects, and one of the objects has five times more mass than the other, it will accelerate at one fifth the acceleration of the other.
636216
Assuming a gentle acceleration, a man in a space ship would experience gentle forces as he reached the speed of light.  As measured by outside observers his mass would increase, but he would be unaware of this. However, according to Einsteins theories he would find it took greater and greater energy to keep accelerating his ship at the constant rate, until an infinite amount of energy were required to get to light speed.  He couldn't find that amount of energy, so he would run out of fuel and coast at a velocity less than the speed of light relative to the more or less "fixed" stars as observed by him, or by the stars.