1.
Point A of the circular disk is at the angular position theta = 0 at time t = 0. The disk has angular
velocity omega_o = 0.18 rad/s at t = 0 and subsequently experiences an angular acceleration a =
1.0 omega, where omega is in radians per second, and a is in radians per second squared.
Determine the velocity and acceleration of point A in terms of fixed i and j unit vectors at time t
= 1.02 s.
Solution
at point A
at t= 1.02s
w= w 0 +*t but = 1.0w
w= w 0 +w*1.02 or w= -9 rad sec
velocity will be in upward direction only that is v = rw = 0.175*-9= -1.575 m/s
v=( 0 i -1.575 j ) m/sec
acceleration will have always two component radial component and Tangential component
radial component = a r = rw 2
= 0.175*9 2
=14.175m/s 2
Tangential component = a t = r*= 0.175*(-9) = -1.575 m/sec 2
a= a r *i + a t *j at point A
A= (14.175 i - 1.575 j ) m/sec 2