Advertisements
Advertisements
Question
An enemy plane is at a distance of 300 km from a radar. In how much time the radar will be able to detect the plane? Take velocity of radio waves as 3 × 108 ms−1.
Advertisements
Solution
Distance between the plane and the radar, d = 300 km = 300,000 m
Velocity of radio waves, c = 3 × 108 ms−1
Waves from the radar will travel to the plane and then reflect and travel back to the receiver of the radar. Hence, the total distance traveled by the waves is 2d.
∴ 2d = c × t
:. `t = (2d)/c`
`:. t = (2 xx 300000)/(3 xx 10^8)`
∴ t = 2 × 10−3 s
∴ t = 2 ms
APPEARS IN
RELATED QUESTIONS
Name the factor that determines Quality of the note
The pitch of a stringed instrument is increased by .................. tension in string.
Two waves of the same pitch have amplitudes in the ratio 1:3. What will be the ratio of loudness?
How does the wave pattern of a loud note differ from a soft note? Draw a diagram.
Give scientific reason for the following:
Windows sometimes rattle when the low notes of a pipe organ are sounded.
Name the subjective property of light related to its wavelength.
How do you account for the fact that two strings can be used to give notes of the same pitch and loudness but of different quality?
How is it possible to detect the filling of a pitcher under a tap by hearing its sound at a distance?
What does the intensity of sound depend upon?
Give scientific reason.
In earlier times, people used to listen for the arrival of a distant train by putting their ear to the rail.
