when a car starts its journey on a straight and level road, it accelerates. however, the acceleration becomes less until it reaches a steady speed and cant go faster. even a very powerful engine will not make a difference. Why??
this is the question. pls help. 10 points for the best and most understandable answer.
2006-12-06 23:16:06 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Physics
The car engine will have a limited amount of power, which can only apply so much force to the road.
According to Newton's first law, a body remains in steady motion unless an UNbalanced force acts upon it.
When the car accelerates, the forces acting in the direction of motion is the power applied by the car. The forces acting against it are wind resistance and tire friction. As the car goes faster and faster, the magnitude of wind resistance will increase (in the same way that it's harder to walk into a strong wind than it is if there's no wind) until the forces are balanced and the acceleration ceases. The wind resistance is the limiting factor and can be reduced by making the car more aerodynamic.
2006-12-06 23:44:55 · answer #1 · answered by Morgy 4 · 0⤊ 0⤋
Everybody seems to have missed the most obvious answer. The car must be traveling at the speed of light! If the car was traveling at the speed of light there would be no way it could ever get faster.
Of coarse, the car has mass and therefore can never reach the speed of light. So here's another suggestion:
Air resistance is a reactive force. The faster an object moves the more the air resistance acts to slow that object down. This is not a linear relationship so there will come a point where you can not accelerate any faster: the more energy you try to put into motion the more you put into the resistive force.
Maybe?
I still prefer my speed-of-light answer.
2006-12-07 01:16:03 · answer #2 · answered by Mawkish 4 · 0⤊ 0⤋
This is caused by friction.
Friction on a object (ie car) depends on (among others) the speed of the object. F = X * v. (This is an approximation of the real behaviour)
This force will cause an acceleration opposite to the moving direction with size a = F/m = Xv/m = dv/dt.
(v = speed, m = mass, X = constant).
So friction increases when speed increases and the car will stop accelerating until a balance if found between driving force and friction force.
a_dr = a_fr --> F_dr/m = Xv/m --> F_dr = Xv
So terminal velocity is v = F_dr / X.
The constant X depends on material and shape of the object.
This also applies for falling objects.
2006-12-06 23:57:21 · answer #3 · answered by anton3s 3 · 0⤊ 0⤋
Boy, you have reached the maximum Engine speed [rpm].
There is a maximum ratio that the gears and transmission will deliver to the wheels.
For further increase in speed, ie, acceleration, you need to have an engine with a higher rpm, not just power.
The impact of wind resistance, friction, heat-up and all can be overcome by having a higher power engine, better cooling, better tyres and so on, but still the limitation will be the engine rpm.
[rpm= rounds per minute=speed,
maximum engine rpm= maximum number of complete cycles of strokes the engine will make]
2006-12-06 23:50:52 · answer #4 · answered by kapilbansalagra 4 · 0⤊ 0⤋
Every travelling machine that man has built has a limit of speed that it cannot exceed. A car too has its limitations. You can accelerate it till it reaches its maximum speed say, 160 km per hour. After that, it will not accelerate no matter how much you try.
I know this answer is not so 'physics' but it's the best reason why the situation is true.
2006-12-06 23:26:15 · answer #5 · answered by Akilesh - Internet Undertaker 7 · 0⤊ 0⤋
with each meter/sec faster you make the car go the more air resistance the car builds up, so to get (say) from 25 to 26 m/s it may take 100Newtons, then from 26 to 27 m/s it may take 110Newtons. so eventually the car will reach it's top speed (terminal velocity) because the engine will not be able to produce enough force to overcome the resistance to motion.
(numbers used in estimate are not in any way accurate)
2006-12-06 23:45:09 · answer #6 · answered by william k 2 · 0⤊ 0⤋
The car will stop to accelerate when the force driving it forward and that holding it back are equal. This will usually be friction in the car and drag caused by wind resistance.
2006-12-06 23:27:45 · answer #7 · answered by Gene 7 · 0⤊ 0⤋
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2016-10-05 00:04:32 · answer #8 · answered by ? 4 · 0⤊ 0⤋
The simplest answer I can give is, for ever action there is a counter action. not only vertical , but horizontally.
Mechanical engineering teaches for ever positive force , there is a negative to keep things in balance.
Popular theory that we can not exceed the speed of light.
In order to do this you have to apply different rules, and theories.
I'm not answering the question out right but giving advise that applies to the question for you to answer.
2006-12-07 00:31:41 · answer #9 · answered by Anonymous · 0⤊ 0⤋