Answer:
The observed frequency by the pedestrian is 424 Hz.
Explanation:
Given;
frequency of the source, Fs = 400 Hz
speed of the car as it approaches the stationary observer, Vs = 20 m/s
Based on Doppler effect, as the car the approaches the stationary observer, the observed frequency will be higher than the transmitted (source) frequency because of decrease in distance between the car and the observer.
The observed frequency is calculated as;
![F_s = F_o [\frac{v}{v_s + v} ] \\\\](https://tex.z-dn.net/?f=F_s%20%3D%20F_o%20%5B%5Cfrac%7Bv%7D%7Bv_s%20%2B%20v%7D%20%5D%20%5C%5C%5C%5C)
where;
F₀ is the observed frequency
v is the speed of sound in air = 340 m/s
![F_s = F_o [\frac{v}{v_s + v} ] \\\\400 = F_o [\frac{340}{20 + 340} ] \\\\400 = F_o (0.9444) \\\\F_o = \frac{400}{0.9444} \\\\F_o = 423.55 \ Hz \\](https://tex.z-dn.net/?f=F_s%20%3D%20F_o%20%5B%5Cfrac%7Bv%7D%7Bv_s%20%2B%20v%7D%20%5D%20%5C%5C%5C%5C400%20%3D%20F_o%20%5B%5Cfrac%7B340%7D%7B20%20%2B%20340%7D%20%5D%20%5C%5C%5C%5C400%20%3D%20F_o%20%280.9444%29%20%5C%5C%5C%5CF_o%20%3D%20%5Cfrac%7B400%7D%7B0.9444%7D%20%5C%5C%5C%5CF_o%20%3D%20423.55%20%5C%20Hz%20%5C%5C)
F₀ ≅ 424 Hz.
Therefore, the observed frequency by the pedestrian is 424 Hz.
The statement “Electrons are pulled closer to the oxygen
atom” correctly describes the electrons in a water molecule. The
correct answer between all the choices given is the second choice or letter B. I
am hoping that this answer has satisfied your query and it will be able to help
you in your endeavor, and if you would like, feel free to ask another question.
Ok i will answer for real this time. Please give me brainliest.
<span>The Answerr is:
5.12*10^15. Since e=h*f, f=e/h. 3.4*10^(-18)/h.
</span>i am so sorry i was doing a challenge and i needed answers to get 100 pts.
Hope I Helped
~TeenOlafLover <3
Answer:
7.1 m/s
Explanation:
First, find the time it takes for the fish to reach the water.
Given in the y direction:
Δy = 6.1 m
v₀ = 0 m/s
a = 9.8 m/s²
Find: t
Δy = v₀ t + ½ at²
6.1 m = (0 m/s) t + ½ (9.8 m/s²) t²
t = 1.12 s
Next, find the velocity needed to travel 7.9 m in that time.
Given in the x direction:
Δx = 7.9 m
a = 0 m/s²
t = 1.12 s
Find: v₀
Δx = v₀ t + ½ at²
7.9 m = v₀ (1.12 s) + ½ (0 m/s²) (1.12 s)²
v₀ = 7.1 m/s
