Answer:
<em>D. refraction</em>
Explanation:
Refraction: Refraction is change in direction of light rays. Refraction occurs whenever light rays travels from a transparent medium to another transparent medium of different density. The abrupt change in direction at the surface of the surface of the two media is referred to as <em>refraction</em><em>.</em>
<em>Refraction occurs when light travels from air to glass or from air to liquid.</em>
<em>Laws Of Refraction:</em>
(i) The incident ray, the refracted ray and the normal, all at the point of incident lies in the same plane.
(ii) The ratio of the sine of the angle of incident to the sine of the angle of refraction is a constant for a given pair of media.
<em>Thus the right option is D. refraction</em>
Given:
u(initial velocity)=0
a=5.54m/s^2
v(final velocity)=2 m/s
v=u +at
Where v is the final velocity.
u is the initial velocity
a is the acceleration.
t is the time
2=0+5.54t
t=2/5.54
t=0.36 sec
Given:
initial angular speed, = 21.5 rad/s
final angular speed, = 28.0 rad/s
time, t = 3.50 s
Solution:
Angular acceleration can be defined as the time rate of change of angular velocity and is given by:
Now, putting the given values in the above formula:
Therefore, angular acceleration is: