Answer:
145 m
Explanation:
Given:
Wavelength (λ) = 2.9 m
we know,
c = f × λ
where,
c = speed of light ; 3.0 x 10⁸ m/s
f = frequency
thus,
![f=\frac{c}{\lambda}](https://tex.z-dn.net/?f=f%3D%5Cfrac%7Bc%7D%7B%5Clambda%7D)
substituting the values in the equation we get,
![f=\frac{3.0\times 10^8 m/s}{2.9m}](https://tex.z-dn.net/?f=f%3D%5Cfrac%7B3.0%5Ctimes%2010%5E8%20m%2Fs%7D%7B2.9m%7D)
f = 1.03 x 10⁸Hz
Now,
The time period (T) = ![\frac{1}{f}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bf%7D)
or
T =
= 9.6 x 10⁻⁹ seconds
thus,
the time interval of one pulse = 100T = 9.6 x 10⁻⁷ s
Time between pulses = (100T×10) = 9.6 x 10⁻⁶ s
Now,
For radar to detect the object the pulse must hit the object and come back to the detector.
Hence, the shortest distance will be half the distance travelled by the pulse back and forth.
Distance = speed × time = 3 x 10^8 m/s × 9.6 x 10⁻⁷ s) = 290 m {Back and forth}
Thus, the minimum distance to target =
= 145 m
Average velocity is 1..2 mi/min east
Explanation:
- Velocity = Displacement/Time
Here, displacement = 48 mi - 42 mi = 6 miles
Time = 5 minutes
⇒ Average Velocity = 6/5 = 1.2 mi/min east
The kinetic energy of the wind ==> causes ==>
the windmill to turn (mechanical energy) ==>
which is used to turn an electric generator ==>
which generates electrical energy.
Answer: Non metal.
Explanation: Carbon has 4 electrons in it’s valence shell which makes it a metalloid but commonly it is considered as a non metal.
I think it is d if not then im sorry