What is the acceleration of a car at constant speed?

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A car traveling at a constant speed, such as 60 MPH, has zero acceleration when resistive forces are not considered. However, to maintain this constant speed against drag and rolling resistance, the engine must exert a force to counteract these opposing forces. This means that while the car's speed remains constant, the acceleration is technically zero because there is no change in velocity. The confusion often arises from misunderstanding the definitions of speed, velocity, and acceleration. Ultimately, constant speed equates to zero acceleration, regardless of the forces acting on the vehicle.
BoredButCurious
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If a car is traveling at a constant speed of say, 60MPH, is the acceleration of the car 0, or is it equal to the drag and rolling resistance it's facing?
 
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BoredButCurious said:
If a car is traveling at a constant speed of say, 60MPH, is the acceleration of the car 0, or is it equal to the drag and rolling resistance it's facing?
What do you think and why? What is the definition of acceleration?
 
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If not considering resistive forces, the acceleration is zero.
But if we do consider them, then they are always opposing the motion of the car. To keep the velocity of the car constant, the engine has to be kept running, else resistive forces slow u down to rest.
So, a force is applied by the engine just to overcome the resistive forces to keep the car moving with constant velocity.
I hope you understood :-)
 
BoredButCurious said:
If a car is traveling at a constant speed of say, 60MPH, is the acceleration of the car 0, or is it equal to the drag and rolling resistance it's facing?

Read your question again. The last part asks if an acceleration (the acceleration of the car) is equal to a force (drag/rolling resistances are forces). That cannot be correct.
 
You should also distinguish between speed and velocity is you are dealing with Acceleration in a thorough way.
 
[USER=569844]@navin[/USER] said:
If not considering resistive forces, the acceleration is zero.
But if we do consider them, then they are always opposing the motion of the car. To keep the velocity of the car constant, the engine has to be kept running, else resistive forces slow u down to rest.
So, a force is applied by the engine just to overcome the resistive forces to keep the car moving with constant velocity.
I hope you understood :-)

I'm sorry but your explanation is overly complicated and confusing and has little to do with the OP's question.

BoredButCurious said:
If a car is traveling at a constant speed of say, 60MPH, is the acceleration of the car 0, or is it equal to the drag and rolling resistance it's facing?

As Phinds said, look at the definition of acceleration: the rate of change of velocity.
 
As pointed out already, all such confusion arises because of not completely understanding a definition. First, constant speed does not mean zero acceleration. An object could be going on a curved path at constant speed. The object has an acceleration. Zero acceleration means constant velocity. Also to be noticed is that the definition of acceleration does not involve any information about forces. Acceleration is a kinematic quantity. Irrespective of what forces are acting, if the velocity is constant, the acceleration is zero.
 

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