Answer:
if the frequency is double, the wavelength is only half as long
Explanation:
Answer:
The velocity of the blades is 88.185 m/s.
Explanation:
Given;
length of the blade, r = 80 m
angular speed, ω = 1 rev per 5.7 seconds
The velocity of the blades is calculated by applying the following circular motion equation that relates linear velocity (V) and angular speed (ω);

Therefore, the velocity of the blades is 88.185 m/s.
Answer:
(a) 9.36 kHz
(b) 3.12 kHz
Explanation:
(a)
V = speed of sound
= speed of airplane = (0.5) V
f = actual frequency of sound emitted by airplane = 4.68 kHz = 4680 Hz
f' = Frequency heard by the stationary listener
Using Doppler's effect


f' = 9360 Hz
f' = 9.36 kHz
(b)
V = speed of sound
= speed of airplane = (0.5) V
f = actual frequency of sound emitted by airplane = 4.68 kHz = 4680 Hz
f' = Frequency heard by the stationary listener
Using Doppler's effect


f' = 3120 Hz
f' = 3.12 kHz
Answer:
Wy = - 268.3*cos(42) = - 199.38 [N]
Wx = 268.3*sin(42) = 179.52 [N]
Explanation:
To solve this problem we must make a free body diagram, in the attached image we can see a free body diagram.
Taking the inclined X & y axes with the same angle of 42°, we can see that the weight can be decomposed on both axes.
Since the angle is adjacent to the y-axis, we can use the cosine function
Wy = - 268.3*cos(42) = - 199.38 [N]
Wx = 268.3*sin(42) = 179.52 [N]