The locus of the centre of a wheel rolling on a straight road is a ______

The locus of the centre of a wheel of a bicycle going straight along a level road.

The speed of the centre of a wheel rolling on a horizontal horizontal surface is v_(0) . A point on the rim in level with the centre will be moving at a speed of speed of:

A car moving on a straight road is an example of:

The centre of a wheel rolling on a plaen surface moves with a speed v_0 . A particle on the rim of the wheel at the same level as the centre will be moving at speed

The centre of a wheel rolling on a plane surface moves with a speed v_0 . A particle on the rim of the wheel at the same level as the centre will be moving at a speed sqrt(x) v_0 . Then the value of x is ______ .