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

if a star is moving toward earth, its light waves appear to be squeezed together. hope it

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force