The answer is the FIRST OPTION
Work occurs when a force is applied to an object and the object moves in the direction of the force applied <span />
Answer:
4 m/s
Explanation:
Momentum is defined as:

where
m is the mass of the object
v is its velocity
For the object in this problem, we know:
p = 200 kg m/s is the momentum
m = 50 kg is the mass
Solving for the velocity, we find:

We will hear the sound of siren of frequency 1553.4606 Hz.
<h3>What is Doppler Effect?</h3>
The apparent change in wave frequency brought on by the movement of a wave source is known as the Doppler effect. When the wave source is coming closer and when it is moving away, the perceived frequency changes. The Doppler effect explains why we hear a passing siren's sound changing in pitch.
according to Dopplers Effect,
![f'=[\frac{v + v_{0} }{v - v_{s} } ]f](https://tex.z-dn.net/?f=f%27%3D%5B%5Cfrac%7Bv%20%2B%20v_%7B0%7D%20%7D%7Bv%20-%20v_%7Bs%7D%20%7D%20%5Df)
![f'= [\frac{700+68.1}{700-94.8} ]* 1224](https://tex.z-dn.net/?f=f%27%3D%20%5B%5Cfrac%7B700%2B68.1%7D%7B700-94.8%7D%20%5D%2A%201224)

the frequency would be 1553.4606 Hz.
to learn more about Doppler Effect go to - brainly.com/question/9165991
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Retrograde. Planets seem to move forward and then backward sometimes. This is really because we pass them as we move in our orbit but astronomers wanted to try to describe the solar system with earth at the center so elaborate models were employed.
Answer:
the answer to the question is a system of insulating element designed to control the path of electric current for a particular purpose