A wheel has a constant angular acceleration of 1.8 rad/s2. During a certain 4.0 s interval, it turns through an angle of 45 rad. Assuming that the wheel started from rest, how long had it been in motion before the start of the 4.0 s interval?

4.25 s

Explanation:

Given:

angular acceleration'α'=  1.8 rad/s²

angle 'θ'= 45 rad

time 't'= 4s

initial angular velocity ''=0

as we know that,

θ= t +

45 = 4 + (0.5 x 1.8 x 16)

45- 14.4 = 4

30.6 = 4

= 7.65

Next is to find t by using the equation

=   +

7.65= 0 + (1.8)

= 7.65/1.8

= 4.25 s

Therefore, At the start of 4s interval the motion is at 4.25 second

im guessing the west of station b

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this