A disk rolls along a flat surface at a constant speed of 10 m/s. Its diameter is 0.5 m. At a particular instant, point P on the edge of the disk is 45°from the horizontal. What is the velocity of point P at that instant?

Explanation:

Tangential velocity of point P ( v ) = 10 m/s making an angle of 45°from the horizontal due to rotation of disk.

Linear forward velocity due to linear forward motion of disc

= v = 10 m /s

Resultant velocity R

R²= 10² +10² + 2 . 10 . 10 cos 45

= 200 + 200 x .707

R = 18.47  m /s .