If the radius of the pedal is extended to be equal to the radius of the wheel or longer, what will it happen?
Torque(pedal) = Force(acted by the cyclist) * Radius (pedal-arm)
A longer pedal means more torque, so the bicycle accelerates faster for the same force provided by the cyclist.
If the...
FINAL ANSWER
"Seeing" and observing are two different things. The latter pertains to measurements, which will show the spaceship to have contracted in the direction of motion.
The contraction can be measured, but the measurement is frame-dependent.
According to Terrel-Penrose...
http://www.spacetimetravel.org/fussball/fussball1.html
"A rigid body which, measured in a state of rest, has the form of a sphere, therefore has in a state of motion - viewed from the stationary system - the form of an ellipsoid of revolution [...]. While the Y- and Z-dimensions of the sphere...
http://www.aps.org/meetings/unit/dpp/vpr2007/upload/vay.pdf
I read this article some time ago and I had the impression that the spaceship would look flattened.
My answer would be:
Length in the direction of velocity is contracted from the point of view of the observer on Earth, so the...
It is a little difficult, I have to admit, and English is not my mother-tongue.
So we can say that the spaceship will look flattened, but it will be a sphere on a film.
So the wheel will move towards P in any case (transportational movement)
In my first picture it will rotate anticlockwise all the time.
In my second picture it will rotate clockwise at the beginning and then?
Let us suppose that the spaceship moves with the x-axis parallel to the earth. The observer on Earth sees this dimension bigger (length contraction in the moving frame), so the shape is now an oblate spheroid. Or is it not?
For the first picture how will we justify that the wheel is moving forward?
Won't we say that this happens because the torque of the tension is bigger?
For the second picture: Initially the wheel is moving backwards because the torque of the static friction is bigger. Then what?
[SOLVED] Bicycle problem
Will the bicycle move forward or backward?
We have 2 forces. The friction and the one we act on the wheel through the string. The weight and the normal force have torque equal to zero.
torque of the friction = T.r1
torque of the F = F.r2
In the second picture r1>r2...