Answer:
I think it's D
Explanation:
because I have seen the tracks of the tires
Given:
Total distance = 1000 kilometer
Total time = 5 hours
To find:
Average speed = ?
Formula used:
= 
Where
= average speed
s = total distance
t = total time
Solution:
Average speed of the jet is given by,
= 
Where
= average speed
s = total distance
t = total time
= 
= 200 km/ h
Thus, average speed of the jet is 200 km/h.
Hence, Option (A) is correct.
Answer:
v = wavelength * frequency
frequency = 5200 m/s / .2 m = 26000 / sec
20,000 / sec is optimistic for the upper frequency of human hearing
So 26,000 is above the hearing range for human ears