Answer:
The recoil speed of the man and rifle is .
Explanation:
The expression for the force in terms of mg is as follows;
F=mg
Here, m is the mass and acceleration due to gravity.
Rearrange the expression for mass.
Calculate the combined mass of the man and rifle.
Put .
The expression for the conservation of momentum is as follows as;
Here, is the mass of the man and rifle, is the mass of the rifle, are the initial velocities of the man and bullet and are the final velocities of the man and rifle and rifle.
It is given in the problem that a rifle with a weight of 25 N fires a 4.5-g bullet with a speed of 240 m/s.
Convert mass of rifle from gram to kilogram.
Put , , , and .
Therefore, the recoil speed of the man and rifle is .
Answer:
B) laws that require scientists to research certain things
The boat’s resultant velocity with respect to North is determined as 17 m/s.
<h3>Resultant velocity of the boat</h3>
The boat’s resultant velocity with respect to North is calculated as follows;
R² = Va² + Vb²
R = √(Va² + Vb²)
R = √(15² + 8²)
R = 17 m/s
Thus, the boat’s resultant velocity with respect to North is determined as 17 m/s.
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Answer:
A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.
Explanation:
In Physics, Doppler effect can be defined as the change in frequency of a wave with respect to an observer in motion and moving relative to the source of the wave.
Simply stated, Doppler effect is the change in wave frequency as a result of the relative motion existing between a wave source and its observer.
The term "Doppler effect" was named after an Austrian mathematician and physicist known as Christian Johann Doppler while studying the starlight in relation to the movement of stars.
<em>The phenomenon of Doppler effects is generally applicable to both sound and light. </em>
An example of the Doppler effect is a police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase. This is so because when a sound object moves towards you, its sound waves frequency increases, thereby causing a higher pitch. However, if the sound object is moving away from the observer, it's sound waves frequency decreases and thus resulting in a lower pitch.
<em>Other fields were the Doppler effects are applied are; astronomy, flow management, vibration measurement, radars, satellite communications etc. </em>
A common activity like cooking a meal can use many natural <u>Ingredients </u>
<h3>Ingredients </h3>
Ingredients are substances combined to make a particular mixture such as a meal. most of the ingredients used for the preparation of a meal are sourced naturally.
In cooking different recipes of a meal the use of specific ingredients for each recipe differentiates the recipes.
Therefore we can conclude that cooking a meal requires the use of natural ingredients.
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