Answer:
The speed of the police car is 294 m/s
Explanation:
Given;
frequency of the siren in air, f = 280 Hz
speed of sound in air, v = 343 m/s
Determine the wavelength of the sound in air to the stationary car:
v = fλ
where;
λ is wavelength of the sound
λ = v/f
λ = 343 / 280
λ = 1.225 m
Now, determine the speed at which the police car is approaching the stationary car;
The actual frequency of the police car, F = 240 Hz
V = Fλ
Where;
V is speed of the police car
λ is the distance between the police car and the stationary car, (wavelength)
V = 240 x 1.225
V = 294 m/s
Therefore, the speed of the police car is 294 m/s
Answer:
Science is the body of knowledge that explores the physical and natural world. Engineering is the application of knowledge in order to design, build and maintain a product or a process that solves a problem and fulfills a need.
Explanation:
Answer:
a = 0,1[m/s^2]
Explanation:
First we need to indentify the initial data.
And using this kinematic equation we have:
![v = 4[m/s]\\v_{0}= 2 [m/s] \\t = 20[s]\\\\v= v_{0}+a*t\\a=\frac{v-v_{0}}{t} \\a= \frac{4-2}{20} \\a=0.1[m/s^{2}]](https://tex.z-dn.net/?f=v%20%3D%204%5Bm%2Fs%5D%5C%5Cv_%7B0%7D%3D%202%20%5Bm%2Fs%5D%20%5C%5Ct%20%3D%2020%5Bs%5D%5C%5C%5C%5Cv%3D%20v_%7B0%7D%2Ba%2At%5C%5Ca%3D%5Cfrac%7Bv-v_%7B0%7D%7D%7Bt%7D%20%5C%5Ca%3D%20%5Cfrac%7B4-2%7D%7B20%7D%20%5C%5Ca%3D0.1%5Bm%2Fs%5E%7B2%7D%5D)
Answer:
The diaphragm.
Explanation:
A diaphragm is a thin non transparent structure with an aperture at its center. Aperture is the opening in a lens through which light passes to enter the camera. Diaphragm controls the passage of light through specimen. It stops the passage of light except for the light passing through aperture. It also limits the brightness of light reaching the focal plane.
The diaphragm is placed close to the lens, where objects are defocused to the maximum in order to pass every ray from the object through the lens. Diaphragm discards some of those rays but allows multiple rays to move through to produce an image. This means that the size of the aperture controls the amount of light that passes through the lens. The center of the aperture coincides with optical axis of the lens. Iris diaphragm is an example. It is used in modern cameras.
Answer:
Your answer will be C. 3.8 kPa.
