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k.udhay
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Hi. I have heard that with high speed of a car, its centre of gravity (CG) shifts backward. Isn't the CG a function of mass and dimension? Pl. explain. Thanks.
xxChrisxx said:Why would it need a reference? It's not a statement of fact, it's a question.
OP, CoG is dependent on mass and the geometry. What happens when you accelerate? And would traveling at any speed matter?
Kozy said:Who ever stated that, probably got CoG and CoP mixed up.
At a steady speed, the CoG is static, regardless of the speed.
The CoP changes according to the aerodynamics of the vehicle and the speed at which it is travelling.
k.udhay said:Well, I am unable to imagine the effect during acceleration of a rigid body. My body bends back when I accelerate my bike because the bike and I are not rigidly connected. But for the bike, will the acceleration do anything?
AlephZero said:The OP's statement (wherever it came from) might be a garbled explanation of the fact that the weight distribution between the front and back wheels of a vehicle changes when it is accelerating. That does NOT mean that the CG position changes. The basic reason why the weight distribution changes is because the CG is at some distance above the ground level. The higher above the ground level, the bigger the effect (which is one reason why high performance cars are designed to be as low to the ground as possible).
Assuming CoP means the aerodynamic center of pressure, I don't see what relevance that has to the OP's question. In any case, acceleration has no effect on the CoP either. The CoP position might change by a small amount as the speed varies, but speed is not the same as acceleration.
xxChrisxx said:Some things to think about.
1. Is a car a rigid body?
2. You tilt back when you accelerate on your bike, accelerate hard enough you pull a wheelie. Why should a car act any differently?
3. Even in a rigid body, load transfer effects still take place. In a non rigid body you have load and weight transfer. (you can look up the difference on wiki)
k.udhay said:Hi Kozy. Can you pl. explain what as CoP is? Thanks.
k.udhay said:Hi Chris!
1. Though the car is not perfectly rigidly, it is still rigid enough to assume as a theoritically rigid body.
2. I tilt back when acclerating because there is no rigid connection between the bike and me. Secondly, a human body is highly flexible.
3. I agree. I am clear now that CG doesn't shift.
xxChrisxx said:In a non rigid body you have load and weight transfer. (you can look up the difference on wiki)
... often, "here be logic-chopping dragons" ... but actually that page isn't so bad.Weight transfer and load transfer are two expressions used somewhat confusingly to describe two distinct effects:
The center of gravity of a car is the point where the weight of the entire vehicle can be considered to be concentrated. It is usually located at the geometric center of the car, but can shift depending on the distribution of weight in the vehicle.
The center of gravity of a car shifts with speed because as the car accelerates, its weight is transferred to the rear wheels, causing the front of the car to rise and the rear to lower. This shift in weight distribution affects the location of the center of gravity.
The location of the center of gravity is directly related to a car's stability. A car with a low center of gravity will be more stable and less likely to roll over, while a car with a high center of gravity will be more prone to tipping.
Yes, the center of gravity of a car can be adjusted by modifying the weight distribution within the vehicle. This can be achieved by changing the placement of heavy components, such as the engine or fuel tank, or by adding weight to specific areas of the car.
If the center of gravity of a car is too high, the car will be less stable and more prone to tipping over, especially during sharp turns or sudden changes in direction. This can be dangerous and increase the risk of accidents, so it is important to maintain a proper center of gravity for optimal vehicle performance.