Understanding Tangential vs. Radial Acceleration on Rotating Bodies in Physics

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Tangential acceleration refers to the change in the speed of a point on a rotating body, while radial acceleration pertains to the change in direction of that point's velocity. Lower tire pressure increases the contact area between the tire and pavement because the tire 'slumps' more, distributing weight over a larger surface. The contact area for air-pressure-based tires is determined by the weight carried divided by the tire pressure, whereas modern car tires rely on sidewall support, making them less sensitive to pressure changes. Rotational and translational motions are distinct; a force can influence both simultaneously, but they operate independently. Understanding these concepts is crucial for analyzing the dynamics of rotating bodies and their interactions with surfaces.
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What is the difference between tangential and radial acceleration for a point on a rotating body? :rolleyes:
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Also, and this is mainly for a personal inquiry trying to get a "physics-oriented" answer...
I've noticed that the lower the tire pressure the greater the contact area between the tire and the pavement... why?
 
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Draw a circle. Now label the tangential and radial directions. Remember, orthogonal (different by 90 degrees) components cannot affect each other directly.

About tire-pavement surface area versus tire pressure: there probably isn't a "physics-oriented" answer. It's just a simple observational fact that, if you lower the pressure, the tire tends to 'slump' more and because of that, there is more of it touching the ground.
 
mezarashi said:
About tire-pavement surface area versus tire pressure: there probably isn't a "physics-oriented" answer. It's just a simple observational fact that, if you lower the pressure, the tire tends to 'slump' more and because of that, there is more of it touching the ground.

Actually:
For an air-pressure based tire - like normal bycicle - the area of the tire that touches the ground is goint to be equal to the weight that the tire is carrying divided by the pressure in the tire.

Modern car tires use a somewhat different tenchology where a non-trivial amount of the weight is carried by the side walls of the tire, and, as a consequence, the area that makes contact with the ground is affected less by the air pressure in the tire.
 
also related to rotational motion... a concept that I can't grasp entirely...
can a simple force applied to a body change both its translational and the rotational motion?
I thought they were the same thing...
 
9danny said:
also related to rotational motion... a concept that I can't grasp entirely...
can a simple force applied to a body change both its translational and the rotational motion?
I thought they were the same thing...

Rotational and translational motion are not the same thing.

Consider:
A stationary bycicle wheel has no rotational or translational motion.
If you lift it by the axle, a bycicle wheel could be spinning in place with rotational, but no translational motion.
A bycicle wheel on the back of a moving truck will have translational, but not rotational motion.
And, if you're riding the bycicle, it will have both rotational, and translational motion.
 
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