Answer:
Wave X has a shorter wavelength.
Explanation:
It is given that, two sound waves (wave X and wave Y) are moving through a medium at the same speed.
Speed of a wave is given by :

Where,
is frequency
is wavelength
The relation between the frequency and the wavelength is inverse. Wave X has greater frequency than Y, then wave X has a shorter wavelength.
Hence, the correct option is (B) "has a shorter wavelength".
Answer:
40
Explanation:
If it is a flat mirror, the reflection and incidence are the same -- 40 degrees.
If it is anything else, more information is needed.
Answer:
option A is correct as 1 yard consist of 0.9144 meter which is less than one meter
Explanation:
from the above given statement option 1 is true
1 yard is equal to 0.9144 meter
while
1 mile is equal to 1.60934 km
1 foot is equal to 30.48 centimeter
1 inch is equal to 2.54 centimeter
therefore all these units [left one] are larger than their respective conversion [ right one unit]
therefore option A is correct as 1 yard consist of 0.9144 meter which is less than one meter
30km. 24 the first two hours and 6 the half hour