The Lost Wheel Thread

[FiF]

otolith said:

Kawasicki said:

Nothing unusual there, nothing freaky either.

Would you say that it’s usual for a bouncing object to bounce higher each time it hits the ground? The transfer of energy from rotation to translation is very obvious there.

Off topic but I'm thinking of a cricket delivery from a decent spinner, lots of rotation, and occasionally the ball really grips "something" and spits upwards off the wicket. Poor analogy I know, but another one where, to my eyes holding the bat, it appears to increase speed having converted rotational energy and thus an increase in lateral energy.

[otolith]

Exactly the same thing, change in velocity due to force exerted by contact of a rotating object with the surface.

[TheDrBrian]

FiF said:

otolith said:

Kawasicki said:

Nothing unusual there, nothing freaky either.

Would you say that it’s usual for a bouncing object to bounce higher each time it hits the ground? The transfer of energy from rotation to translation is very obvious there.

Off topic but I'm thinking of a cricket delivery from a decent spinner, lots of rotation, and occasionally the ball really grips "something" and spits upwards off the wicket. Poor analogy I know, but another one where, to my eyes holding the bat, it appears to increase speed having converted rotational energy and thus an increase in lateral energy.

But the surface rotational speed of that ball is faster than linear speed the person has flung it.
The surface rotational speed of the tyre is only ever as fast as it’s linear speed and it can’t go any faster.

• unless you were doing burnouts.

[FiF]

TheDrBrian said:

FiF said:

otolith said:

Kawasicki said:

Nothing unusual there, nothing freaky either.

Would you say that it’s usual for a bouncing object to bounce higher each time it hits the ground? The transfer of energy from rotation to translation is very obvious there.

Off topic but I'm thinking of a cricket delivery from a decent spinner, lots of rotation, and occasionally the ball really grips "something" and spits upwards off the wicket. Poor analogy I know, but another one where, to my eyes holding the bat, it appears to increase speed having converted rotational energy and thus an increase in lateral energy.

But the surface rotational speed of that ball is faster than linear speed the person has flung it.
The surface rotational speed of the tyre is only ever as fast as it’s linear speed and it can’t go any faster.

• unless you were doing burnouts.

That's why I said it was off topic, and was simply an illustration of rotational energy being converted into linear energy, plus the ball bouncing more than it would naturally. Also in case you missed it the possible reason for wheel acceleration due to wheel spinning faster than speed of travel was covered in the original post, i.e. during a drifting competition.

[otolith]

TheDrBrian said:

But the surface rotational speed of that ball is faster than linear speed the person has flung it.
The surface rotational speed of the tyre is only ever as fast as it’s linear speed and it can’t go any faster.

It can’t *roll* any faster. If you look at any of the videos of runaway tyres, they’re not rolling, they’re bouncing.

[Flying Phil]

I was towing a trailer and a wheel came off (my fault as I had not checked the wheel nuts) it did overtake me - and I was not braking when it did. I think it was accelerated by the last stud pushing down as the suspension unloaded.