Answer:
-3.396 m/s or 3.465 m/s
Explanation:
v = Speed of sound in air = 343 m/s
= Relative speed of the singer
f = Observed frequency
f' = Actual frequency
1% change can mean 
From the Doppler effect equation we have
The velocity is -3.396 m/s
when 
The velocity is 3.465 m/s
Answer:
The decrease of these factors increases the acceleration.
Explanation:
Hi, the decrease of these factors increases the acceleration.
Air resistance is a force opposing the acceleration. So if it decreases, the acceleration increases, because the opposite forces decreases.
The same is applied to the force of gravity, since the rocket travels upward; gravity is also an opposite force.
Finally, if the mass decreases, it means that the rocket becomes lighter and the force acting on the smaller mass causes an increase in the acceleration.
The car has an initial velocity 
of 23 m/s and a final velocity 
of 0 m/s. Recall that for constant acceleration,
The car stops in 7 s, so the acceleration is
<h2>Answer: Resonance
</h2>
Resonance is a phenomenon that occurs when a body capable of vibrating is subjected to the action of a periodic force, whose frequency of vibration approaches the characteristic frequency of vibration (called resonance frequence) of said body. This is due a relatively small force applied in a repeated form, causing the amplitude of the oscillating system to become very large.
In other words, for the specific case of sound waves, this phenomenon occurs when the frequency of the wave that is external to the system or body coincides with the resonance frequency (characteristic frequency that reaches the maximum degree of oscillation) of this system or body.
In these circumstances the body vibrates, progressively increasing the amplitude of movement after each successive actions of the force. However, this effect can be destructive in some rigid materials.
Answer
given,
Speed of car A = 95 Km/h
= 95 x 0.278 = 26.41 m/s
Speed of Car B = 121 Km/h
= 121 x 0.278 = 33.64 m/s
Distance between Car A and B at t=0 = 41 Km
a) Distance travel by car B
d = 26.41 t + 41000
speed of the car A = 33.64 m/s
distance = s x t
26.41 t + 41000 = 33.64 x t
7.23 t = 41000
t = 5670.82 s
time taken by Car B to cross Car A is equal to t = 5670.82 s
distance traveled by car A
D = s x t = 26.41 x 5670.82 = 149766.25 m = 149.76 Km
b) distance travel by the car B in 30 s after overtaking car A
D' = s x t = 33.64 x 30 = 1009.2 m = 1 Km
