Based on Newton's principle, whenever objects A and B interact with each other, they exert forces upon each other.
When a horse pulls on a cart, t<span>he horse exerts a force only to the cart. But that force applies only to the cart, not to the horse.
The cart in turn exerts a force on the horse. But that force applies only to the horse, not the cart also.
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There are two forces resulting from this interaction - a force on the horse and a force on the cart. T<span>he net force on the cart remains as it was --- a positive force in the direction of the horse's movement. Therefore, the cart begins to accelerate and move.</span><span>
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The answer is B.
Temperature is just another term for the average kinetic energy of a substance.
Answer:
is reflected back into the region of higher index
Explanation:
Total internal reflection is a phenomenon that occurs when all the light passing from a region of higher index of refraction to a region of lower index is reflected back into the region of higher index.
According to Snell's law, refraction of ligth is described by the equation
where
n1 is the refractive index of the first medium
n2 is the refractive index of the second medium
is the angle of incidence (in the first medium)
is the angle of refraction (in the second medium)
Let's now consider a situation in which
so light is moving from a medium with higher index to a medium with lower index. We can re-write the equation as
Where 
is a number greater than 1. This means that above a certain value of the angle of incidence , the term on the right can become greater than 1. So this would mean
But this is not possible (the sine cannot be larger than 1), so no refraction occurs in this case, and all the light is reflected back into the initial medium (total internal reflection). The value of the angle of incidence above which this phenomen occurs is called critical angle, and it is given by
<h2>Frequency of trumpet wire = 445 Hz</h2>
Explanation:
The given frequency of tuning fork is 440 Hz . It produces 5 beats with trumpet wire . That means , the frequency of wire can be 440 ± 5
It can be either 445 or 435
Now the length of wire is increased , by which its frequency decreases . Because frequency is inversely proportional to length of wire .
If we decrease the frequency in 435 , the difference between tuning fork frequency and wire frequency will become greater than 5 even . So it cannot produce 3 beats with it .
If we decrease frequency from 445 , it can become 443 Hz . It gives 3 beat with the tuning fork as given .
Thus the initial frequency of wire is 445 Hz
