<span> 1) When light is passing from a denser medium to a lighter medium ( for eg: from water to air)
2) When the angle of refraction is greater than the critical angle( angle of incidence when the angle of refraction is perpendicular to the normal) of the denser medium. </span>
Answer:
o to increase the frequency of sound waves. It increases the sound waves to a level of frequency that humans cannot hear so you won't be able to hear many things though the wall other then low noises like pounding.
Explanation:
I am in construction class as well as a student teacher for other construction type programs trust me :D
Brainiest would be appreciated
(A) Standing waves are created by two identical waves reflecting off each other
(B) a general definition of a wave interference is, when more than on wave meet and interact in the same medium
Hope this helps :)
Answer:
Balancing of forces,
In the X-direction:
-Tcos4.5^o +Tcos4.5^o=0
In the Y-direction:
Tsin4.5^o +Tsin4.5^o-m*g=0
2Tsin4.5^o=15*9.81
T=(15*9.81)/(2sin4.5^o)
=937.75 N
Therefore, tension in the rope is 937.75 N.
