Answer:1384 Hz
Explanation:
Given
wavelength
=0.25 m
Temperature T
at 
velocity of sound is 346 m/s
and we know
f=1384 Hz
Answer:
22cm
Explanation:
focal length = 11cm
radius of curvature,r = 2f
r= 2 x 11
r=22cm
Answer:
Radio stations have dipole type antennas
this field increases in intensity and propagates outwards,
Explanation:
Radio stations have dipole type antennas, that is, all sides are isolated from each other, when the AC signal from the radio station arrives, the lcharge begins at times and by the Lens law a field appears that opposes this movement, this field increases in intensity and propagates outwards, when the voltage reaches a maximum, the generated wave also reaches the maximum, now the incident wave begins to decrease, an electric hand appears to oppose this prisoner, and in this way a cap is created. electric .
Using lens equation;
1/o + 1/i = 1/f; where o = Object distance, i = image distance (normally negative), f = focal length (normally negative)
Substituting;
1/o + 1/-30 = 1/-43 => 1/o = -1/43 + 1/30 = 0.01 => o = 1/0.01 = 99.23 cm
Therefore, the object should be place 99.23 cm from the lens.
The speed of bullet =
850 m/s
Distance given = 1 km = 1000m
S = D/t
t • S = D/t • t
St = D
St/S = D/S
t = D/S
t = 1000m/850m/s
t = 1.176 s
It will take the bullet 1.176 or about 1.18 seconds to go 1 km.
