Turning the wheel accelerates the car, but it need not include a change of speed. Right?
Turning the wheel accelerates the car, but it need not include a change of speed. Right?
Turning the wheel accelerates the car, but it need not include a change of speed. Right?
Well, technically -- on a race track, at least -- turning the steering wheel slows the car down...
Aaron
@SrMi has written:Turning the wheel accelerates the car, but it need not include a change of speed. Right?
Well, technically -- on a race track, at least -- turning the steering wheel slows the car down...
Aaron
Slowing the car down = negative acceleration. However, in this context, any change in the velocity vector (magnitude or direction) is called acceleration.
@Autonerd has written: @SrMi has written:Turning the wheel accelerates the car, but it need not include a change of speed. Right?
Well, technically -- on a race track, at least -- turning the steering wheel slows the car down...
Aaron
Slowing the car down = negative acceleration. However, in this context, any change in the velocity vector (magnitude or direction) is called acceleration.
This is getting messy very quickly.
Since the turning car is moving in a circle are you referring to its centripetal acceleration?
@SrMi has written: @Autonerd has written: @SrMi has written:Turning the wheel accelerates the car, but it need not include a change of speed. Right?
Well, technically -- on a race track, at least -- turning the steering wheel slows the car down...
Aaron
Slowing the car down = negative acceleration. However, in this context, any change in the velocity vector (magnitude or direction) is called acceleration.
This is getting messy very quickly.
Since the turning car is moving in a circle are you referring to its centripetal acceleration?
It does not need to be centripetal movement.
Joke: a physicist failed the driving test because when asked to accelerate he turned the steering wheel.
Movement is described as a vector. Any change of the vector (length, angle) is considered acceleration.
It does not need to be centripetal movement.
Not sure what you mean.
If a body is moving in a circle then the centripetal acceleration acting on the body is velocity**2/radius, is it not?
Consequently the centripetal force acting on the body is m x v**2/radius where m = mass of the body.
@SrMi has written:It does not need to be centripetal movement.
Not sure what you mean.
If a body is moving in a circle then the centripetal acceleration acting on the body is velocity**2/radius, is it not?
Yes. That is one example of acceleration when changing direction.
@bobn2 has written:No, I meant the speed.
Turning the wheel accelerates the car, but it need not include a change of speed. Right?
IRL it will always result in a change of speed, because the steering mechanism is never 100% efficient, so some energy is always lost changing the direction of the car, even if it's just making the tyres a bit hotter. That's why after a safety car you'll see racing cars steer left and right, to heat up the tyres.
Clearly not. The history of 'sensitivity' in a photographic context is convoluted.
In a general context, 'sensitivity' refers to the size of stimulus necessary to cause a reaction, not the size of that reaction. The smaller a stimulus is necessary the higher the sensitivity. That applies both in general parlance and scientific/engineering usage. In that sense the ISO control does not usually change sensitivity of the sensor (if the sensor has dual conversion gain, it does, but not in proportion to the ISO). At some stage it crept into photographic usage to denote the size of reaction rather than the size of stimulus which went with the idea that 'gain' or 'amplification' changes 'sensitivity'. Generally it doesn't. Applying gain after a transducer does not change the sensitivity of the transducer. I suspect that the misunderstanding is due to radio hams, who are used to an RF gain control increasing the sensitivity of their receiver, but this is due to the specific behaviour of a diode detector - putting gain before the detector does change the minimum signal it can detect. In a sensor we are not putting the gain before the detector.
Anyhow, when digital cameras started to provide the ability to change the ISO, it was described (wrongly) as a 'sensitivity' control due mainly, I suspect, to this bogus RF receiver analogy. CIPA has been promoting this 'sensitivity' description for a long while, whilst ISO has been resistant, even though it adopted CIPA's two novel 'ISO' definitions in 2006. In the 2019 update of the standard it fudged the whole issue by adopting a term 'photographic sensitivity', which essentially says 'Photographic sensitivity is a term for ISO and for historical reasons sometimes it's just called sensitivity'.
Here above is one of the reasons why I joined this forum. Thank you Bob, Iliah, Jim, and all the other knowledgeable people who participate here.
Another very smart person once said: "If you can't explain it simply, you don't understand it well enough."
@SrMi has written: @bobn2 has written:No, I meant the speed.
Turning the wheel accelerates the car, but it need not include a change of speed. Right?
IRL it will always result in a change of speed, because the steering mechanism is never 100% efficient, so some energy is always lost changing the direction of the car, even if it's just making the tyres a bit hotter. That's why after a safety car you'll see racing cars steer left and right, to heat up the tyres.
I was reading this conversation wondering what the heck people were talking about. People may come up with maps and formulas, but anyone who has driven or even watched a race car knows that changing direction scrubs speed. How we can call that acceleration is beyond me.
@bobn2 has written: @SrMi has written: @bobn2 has written:No, I meant the speed.
Turning the wheel accelerates the car, but it need not include a change of speed. Right?
IRL it will always result in a change of speed, because the steering mechanism is never 100% efficient, so some energy is always lost changing the direction of the car, even if it's just making the tyres a bit hotter. That's why after a safety car you'll see racing cars steer left and right, to heat up the tyres.
I was reading this conversation wondering what the heck people were talking about. People may come up with maps and formulas, but anyone who has driven or even watched a race car knows that changing direction scrubs speed. How we can call that acceleration is beyond me.
Acceleration, positive or negative, is the change in velocity divided by the change in time.
@bobn2 has written: @SrMi has written: @bobn2 has written:No, I meant the speed.
Turning the wheel accelerates the car, but it need not include a change of speed. Right?
IRL it will always result in a change of speed, because the steering mechanism is never 100% efficient, so some energy is always lost changing the direction of the car, even if it's just making the tyres a bit hotter. That's why after a safety car you'll see racing cars steer left and right, to heat up the tyres.
I was reading this conversation wondering what the heck people were talking about. People may come up with maps and formulas, but anyone who has driven or even watched a race car knows that changing direction scrubs speed. How we can call that acceleration is beyond me.
Did you ever have physics in school?
I was reading this conversation wondering what the heck people were talking about. People may come up with maps and formulas, but anyone who has driven or even watched a race car knows that changing direction scrubs speed. How we can call that acceleration is beyond me.
Yeah, probably confusing because the common usage of the word "acceleration" includes a negative corollary, "de-acceleration". Indeed, in standard physics the word acceleration is tagged to any change in velocity, which is defined as the speed and direction of an object . Even turning the steering wheel of a moving car changes velocity, as the direction the car is headed is changed.
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@Mackiesback has written: @bobn2 has written: @SrMi has written: @bobn2 has written:No, I meant the speed.
Turning the wheel accelerates the car, but it need not include a change of speed. Right?
IRL it will always result in a change of speed, because the steering mechanism is never 100% efficient, so some energy is always lost changing the direction of the car, even if it's just making the tyres a bit hotter. That's why after a safety car you'll see racing cars steer left and right, to heat up the tyres.
I was reading this conversation wondering what the heck people were talking about. People may come up with maps and formulas, but anyone who has driven or even watched a race car knows that changing direction scrubs speed. How we can call that acceleration is beyond me.
Did you ever have physics in school?
It's actually practical verse purely theoretical physics.
Theoretical physics allows for a 100% efficient steering mechanism whereby steering will not change the speed. In practice the chance of the steering mechanism being 100% efficient is so small to be effectively zero (try steering on an icy road, and you realise that with no friction there is no steering) so steering always changes the speed of a car.
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Is gravity also acceleration? 😋
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