Explain why an object tossed up in a closed moving vehicle lands on the same position?
372574
If the vehicle is moving at a constant speed, then the object is moving forward at that same speed before being tossed. After it is tossed, it continues to move forward at the same speed (as you and the vehicle) because there is nothing to slow it down.\n\nTry tossing the object when the vehicle is accelerating. The object, after being tossed, does not enjoy the acceleration that you and the vehicle do, but instead continues to move forward at the speed it had when tossed, and will land "behind" you. This is the principle behind a famous result of Einstein. If the vehicle has no windows, you can't tell whether the vehicle is accelerating, or standing still with "gravity" pulling tossed objects toward the back of the vehicle. Even if you try to use a beam of light to determine acceleration or gravity, you will get the same bending of the light beam.
850554
The answer is, there is an instant when a thrown object (upwards) reaches a velocity of zero, which is what the dropped object has the instant it is released. From these two instants in time, the response of each object is only to gravity.
969523
if they are both going at the same speed, then the mass,size of the wheel and other considerations have already been take in account, so they both should arrive at the same time.\nGod bless,\ngabe
877424
In the vertical direction earth is pulling the object downward with a force.\n\nAnd all objects are pulled down by the earth with an acceleration given by g = 9.8 m/ s^2.\n\nFirst we consider the vertical motion alone.\n\nIn the vertical direction \nthe initial velocity u = 0.\nthe acceleration  a = g. \nThe time t = t to be found.\nDisplacement in the vertical direction   s  =   180 m.\n\nWe use the equation s = ut + 05 a tt.\n\nUsing this we find t = 6 second.\n\nNow let us consider the horizontal motion.\n\nThe object is released from the plane which was moving with a speed of 20m/s.\n\nThere fore all objects which was in the plane will also have a speed of 20m/s in the horizontal direction.\n\nHence in the horizontal direction the initial speed is 20m/s.\n\nThe acceleration in this direction is zero since no force is acting in this direction.\n\nThe time t is the same as 6 second.\n\nDistance we have to find.\n\nWe use the equation s = ut + 05 a tt.\n\nSince a = 0 the equation reduces to s = ut. = 20 x 6 = 120m\n\nThe horizontal displacement is 120 m.
970347
e, because of the Newton's 1st law: "An object at rest will remain at rest unless acted upon by an external and unbalanced force . An object in motion will remain in motion unless acted upon by an external and unbalanced force". Assuming inertial frame of reference.\nThe object can still have angular acceleration if there are two forces cancelling each other but are applied to an object at different points. \n\nIn real life there is always something that will slow down the object even in space.
12398
The rotational energy you impart to the object when spinning overcomes the force of gravity that would topple a stationary object.  \n\nA total layman's explanation:\n\nA perfect stationary top perfectly balanced will not fall over.  In real life though,it's impossible to perfectly balance a top.  It's shape practically guarantees that its center of gravity will not be directly over the balance point for any practical length of time.  Imperfections in the material will cause a slightly uneven weight distribution, air currents will introduce a small force, and mechanical vibrations will be transmitted through the medium the top rests on.  The upshot of all this is that as soon as the center of mass is no longer over the resting point, gravity is going to pull the top over.  \n\nNow gravity has an acceleration of 32 feet per second squared (if I remember my ancient high school course correctly).  It can only topple the top at a specific speed.  If you spin the top fast enough, any side that gravity tries to "pull down" will translate around so quickly that it literally has no time to fall.  If you were standing on a planet with a much higher gravity, you'd have to spin the top far faster to achieve stability, and if you were on the moon, it would spin for a much longer time. Eventually, however, the top starts to slow and the tip will inscribe little circles.  That action is called "precession".  And of course, eventually the thing drops to the table and the game is all up once it slows enough.\n\nAgain, that's a layman's view of how it works.  Some college physics major is probably going to come in here and make my answer look really foolish.
475251
If I remember correctly from my high-school physics class, it's a combination of gravity and one of Newton's laws of motion - the one that says "an object in motion stays in motion unless acted on by an outside force." So that force keeps it moving around and gravity keeps it from just flying off into space.
445486
Because the up/down motion is independent of the side-side motion. The stone is already going at whatever speed the car is and that doesn't change. The only thing that changes is the up/down part of the motion. For someone outside the car, the stone looks like it goes along a parabolic arc, not just up and down.\n\nThis is related to the relativity of motion. If you are moving uniformly, it is impossible to tell whether you are moving or not unless you look outside the car.
1044764
The law of conservation of momentum holds in this case.\n\nThe initial momentum of the system must equal the final momentum of the system.\nIn this case, we will call the "System" both cars.\n\nCar 1 has a mass (m1) of 1000 kg, velocity (v1) of 20 m/s.\nCar 2 has a mass (m2) of 800 kg and a velocity, in what we will call the negative direction, v2 = -30 m/s.\n\nThe total momentum (P) does not change.\n\nP = P1 + P2\n\nP1 = m1 * v1 = 1000 kg * 20 m/s\nP1 = 20000 kg m/s\n\nP2 = m2 * v2 = 800 kg * -30 m/s\nP2 = -24000 kg m/s\n\nP = 20000 kg m/s + -24000 kg m/s\nP = -4000 kg m/s\n\nSo the resulting 1800 kg mass will have a momentum of -4000 kg m/s, meaning that it will be traveling in the "negative" direction, AKA, South.\n\nP = -4000 kg m/s = 1800 kg * v_f\nv_f = -4000 / 1800\nv_f = -2.22 m/s\n\nThe resulting blob of the two cars which stuck together will be traveling -2.22 m/s South.
71702
If the only factor involved in this would be gravity, the bullet would come back down at the same speed as it went up. But since there are other factors (friction, air, etc), the bullet would come down with less speed than it went up.\n\nThe same would happen with the place where it was fired, it probably wouldnt land on the same spot, since other factors have an effect on the bullet trayectory.\n\nchech the link from digg and wait for the episode of Mythbusters where they solve this myth ...
623548
This happens with fan blades and rims on car tires.\n\nYour eye can only process information so quickly.\nWhen this happens the wheel is turning faster than your eye and brain can process.  So you expect the single point on the wheel to advance to a certain space but it moved so far the next momment your brain can process the information it looks like it is behind where you last saw it.  Therefor it looks like it moved backwards.  This is easier to explain with pictures.  I hope this helps.
297895
We have to insure that the coin is fairly weighted. (if one side is heavier then the other, it could land wrong.)  The horizontal surface must be completely flat.  The coin should be dropped on edge, in a repeatable fashion. (So that whatver drops it isn't angling it or affecting it.
47010
1.  Hurl it spinning into space.  The vehicle will spin around its center of gravity, and its center of gravity will travel in a straight line.\n\n2.  Balance it on a see-saw three ways: upright, on its side, and on one end.  Each balance will define a middle plane that cuts through the vehicle.  The intersection of the three planes is the center of gravity.
878067
As long as neither of the balls starts spinning (or changes the rate at which it's already spinning) after the collision (in which case some of their linear momentum would have been converted to angular momentum), the total linear momentum of the system before and after the collision must be the same.\n\nLet p11 and p21 be the momentum of balls 1 and 2 before the collision; let p12 and p22 be the momenum of balls 1 and 2 after ths collision; and let m be the mass of the balls (which we are told have the same mass).  The momenta are all vector quantities, which I'll write as order pairs of numbers (i.e.,  p = (x,y) = x*i + y*j, where i and j are the unit vectors in the +x and +y directions, respectively).\n\nLet the +x axis be pointed in the east direction, and the +y axis be in the north direction.\n\nThen, writing each \n\np11 = m*(2 m/s, 0 m/s)\np21 = m*(-1.2 m/s, 0 m/s)\np22 = m*(0 m/s, 1.43 m/s)\np12 = m*v12 (v12 is the vector velocity of ball 1 after the collision)\n\nBy conservation of momentum, we have that:\n\np11 + p21 = p12 + p22\n\nm*(2 m/s, 0 m/s) + m*(-1.2 m/s, 0 m/s) = m*v12 + m*(0 m/s, 1.43 m/s)\n\nv12 = ((2 - 1.2 - 0) m/s, (0 + 0 -1.43) m/s)\n\nv12 = (0.8 m/s, -1.43 m/s)\n\nThe speed of ball 1 after the collision is given by:\n\nsqrt((0.8 m/s)^2 + (-1.43 m/s)^2) = 1.639 m/s\n\nThe angle the velocity vector of ball 1 makes with respect to the +x axis after the collision is given by:\n\narctan(-1.43/0.8) = -1.061 radians = -60.776 degrees\n\n(It helps to draw a picture of this to visualize why this relationship holds.)\n\nThe first ball is traveling 60.776 degrees south of east after the collision.
771396
Because gravity is the same - so it has the same effect on both objects.  The larger object will strike the ground with a greater force, but both objects will accelerate at the same rate.
816243
When an object (like the truck) hits a solid wall then the wall forces it to stop suddenly. \n  The wall and the truck have a certain elasticity, though small. When the truck touches the wall it starts pressing on it and the wall bends very little. It bend in a very short time too. During this small period of time the object's momentum changes from "mv" to "0". The force is the ratio F= (m*v) / t. Because t is very small the force exerted is very big and it crushes the truck's front end.
733139
It follows Newton's law that for every action there is an equal and opposite reaction.  It's usually a wheeled vehicle that flings something backward in order to move forward.  The simplest type uses the jet of air escaping from an inflated balloon.