A radar receiver indicates that a pulse return as an echo in 20 μs after it was sent. The reflecting object would be 3000 m away .
Phenomenon of hearing back our own sound is called an echo. It is due to successive reflection of sound waves from the surfaces or obstacles of large size. To hear an echo, there must be a time gap of 0.1 second in original sound and the reflected sound.
Given
time = 20 μs = 20 * 
s
let distance to the reflecting surface be = x
total distance travelled by pulse will be = 2x
speed = 3.0 × 
m/s
distance = speed * time
2x = 3.0 × * 20 *
x = 3000 m
The reflecting object would be 3000 m away
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Explanation:
The Net Force of the object can be written by:
Fnet = ma
where m is the mass of the object in <em>kg</em>
a is the acceleration of the object in <em>m/s^2</em>
Hence by applying the formula we get:
Fnet = (2.0)(3.0)
= 6N
We also know that Net force is also the sum of all forces acting on an object. In this case Friction and the Pushing Force is acting on the object. Hence we can write that:
Fnet = Pushing Force + (-Friction)
6N = 6N - Friction
Friction = 0N
Hence the<u> </u><u>f</u><u>orce of friction is 0N.</u>
An unbalanced force is required to accelerate an object according to Newton's Second Law of Motion.
<h3>
What does Newton's Second Law of Motion state?</h3>
It states that the force applied to the object is equal to the product of mass and acceleration.
- An object will accelerate when the net force applied on the object is more than zero or unbalanced.
- The acceleration is the change in the direction or speed of the object. To achieve acceleration the force must be greater in a direction.
- When force is greater in one the object move in that direction which is known as acceleration.
Therefore, an unbalanced force is required to accelerate an object according to Newton's Second Law of Motion.
Learn more about Newton's Second Law of Motion.:
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L<span>ight with a spectral composition that stimulates all three types of the color sensitive </span>cone cells<span> of the </span>human eye<span> in nearly equal amounts appears white.
</span>
Answer:
Explanation:
The constant speed means that ball is not experimenting acceleration. This elements is modelled by using the following equation of equilibrium:
Now, the exerted force is:
The volume of a sphere is:
Lastly, the force is calculated:
