The amount of diffraction of sound waves depends on the medium the sound wave travels to and the frequency. Diffraction happens as soon as it has been out of the source.
Answer:
Explanation:
Most of this water is locked up in ice, and another 20.9% is found in lakes. Rivers make up 0.49% of surface freshwater. Although rivers account for only a small amount of freshwater, this is where humans get a large portion of their water from.
Answer:
speed is 81.03 mph
direction is N 3.58 W
Explanation:
given data
travel north = 70 mph
Stream current = 12 mph
direction = S 25° E
result due north = 70 mph
to find out
speed and direction
solution
we will get component of resultant that is
v cosθ and v sinθ
so
( 12cos295 , 12 sin295 ) at ( 0, 70)
as that we can say
v sinθ + 12sin295 = 70 ....................1
v cosθ + 12 cos295 = 0 ......................2
so
vcosθ = -5.0714
vsinθ = 80.8756
now by ratio
cosθ /sinθ = -5.0714/ 80.8756
cot θ = -0.0627
θ = 93.58
so direction is N 3.58 W
and
we know
vcosθ = - 12cos295
v = - 12cos295 / cos(93.58)
v = 81.03 mph
so speed is 81.03 mph