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.
An LED is useful because when a current passes through it, it gives out light.
Answer:
If the density of the object is high its molecular arrangement is compact while if the density is lows its molecular arrangement isnt that compact
The electrons making the shock come from the women's body.
<h3>What is Electric shock ?</h3>
When a high voltage current flows through the body, electrical shock results. When someone unintentionally touches an electrical source, this typically occurs. Treatment for both internal and exterior burns may be necessary as part of the aftercare.
The nervous system may be impacted by a shock.
The tissue that makes up nerves presents extremely minimal resistance to the flow of an electric charge. Electric shocks that impact nerves can cause pain, tingling, numbness, weakness, or trouble moving a limb. These effects might disappear with time or remain for good.
How to Prevent from Electrical Shocks –
- Keep the Appliances Away from Moisture and Water.
- Never Connect or Disconnect Under Load.
- Be Careful with Capacitors.
- Use Insulated Tools.
- Turn Off the Power.
- Check for Improper or Faulty Wiring.
- Fix Extension Cord Problems.
to learn more about electric shock go to - brainly.com/question/8822505
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