Q. A wheel of radius $1\, m$ rolls forward half a revolution on a horizontal ground. The magnitude of the displacement of the point of wheel initially in contact with the ground is
AMUAMU 2002
Solution:
After half a revolution, vertical distance travelled by point
$=\frac{1}{2}$ times circumference of wheel
$=\pi r$
$=\pi$ metre
Total displacement of point
$=\sqrt{\pi^{2}+2^{2}}=\sqrt{\pi^{2}+4}$

