A) volume = length*width*height
so the volume = 10*2*2
= 40cm^2
Wavelength = speed / frequency.
Wavelength = 3x10^8 m/s / 30 hz
Wavelength = 10 million meters
1/2 wavelength = 5 million meters
(that's about 3,100 miles)
I'm pretty sure the frequency is wrong in the question.
I think it's actually 30 kHz, not 30 Hz.
That makes the antenna about 3.1 miles long.
Answer:
The appropriate answer is "72.8 m".
Explanation:
Let the distance be "x".
As per the question, we get
⇒ 
or,
⇒ 
By taking L.C.M, we get
⇒ 
By applying cross-multiplication, we get
⇒ 
⇒ 
⇒ 
Answer:
t = 13.43 s
Explanation:
In order to find the minimum time required by the plane to stop, we will use the first equation of motion. The first equation of motion is written as follows:
Vf = Vi + at
where,
Vf = Final Velocity of the Plane = 0 m/s (Since, the plane finally stops)
Vi = Initial Velocity of the Plane = 95 m/s
a = deceleration of the plane = - 7.07 m/s²
t = minimum time interval needed to stop the plane = ?
Therefore,
0 m/s = 95 m/s + (- 7.07 m/s²)t
t = (95 m/s)/(7.07 m/s²)
<u>t = 13.43 s</u>
