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- angular acceleration ;
- linear velocity .
Solution
2 3
Substitute time t  4 s in equation   At  Bt  Ct and obtain

  204 rad . Take to account, that one revolution conforms 2 rad
number of revolution is equal to
204rad
N   32.
2 , 3  14rad

We defined instantaneous angular velocity and instantaneous
angular acceleration as appropriate derivates:

d 2 rad
   A  2Bt  3Ct  131 ,
dt s

d rad
  2 B 6Ct  56 .
dt s 2
By relationship between linear and angular velocities

v   r  131 1 , 0  13 m .
s

The angular velocity of bicycle wheel is 4 rad at time t 0, and
s
its angular acceleration is constant

and equal to 2 rad 2 . A line OP in
s
the body is horizontal at time t 0
a)What angle does this line make
with the horizontal direction at time
t  s 3

b)What is the angular velocity at
this time?
Solution

Figure 2.4

2
t   rad 1 rad 2
   0    t   0  4  s 3  4 ( 9 s )  21 rad 
a) 2 s 2 s
21
  , 3 34 revolution s
2
The body turns three complete revolutions plus 0,34 rev.Therefore

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