Answer:
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Explanation:
Hope it will be helpful for you...
Answer:
All of the following are true EXCEPT, the angle of refraction is 30 degrees
Explanation:
It is given that,
The index of refraction of the water is 1.33 and the angle of incidence is 30 degrees. We know that when a ray of white light moves through the air and strikes the surface of water in a beaker, refraction occurs. Let r is the angle of refraction. It can be calculated using Snell's law as :
So, the angle of refraction is 22.08 degrees.
According to the law of reflection, the angle of incidence is equal to the angle of reflection. Since, it is incident at an angle of 30 degrees, so the angle of reflection will be 30 degrees. Also, total internal reflection will result, depending on the critical angle.
So, the wrong statement is the angle of refraction is 30 degrees. It is equal to 22.08 degrees.
Consider that I'm an italian student so I may unproperly use some terms.
Being Ug (Potential energy on earth) = m·g·h
Where "m" in this case is the mass of the ball, "g" the average value of gravitation constant on Earth's surface and "h" the height reached by the ball.
The solution to the first question would be : Ug = mgh = 40[kg] · 10 [m/s²] · 5[m] = 2000 [Joule]
In order to find the value of its K (kinetic energy) and without considering air resistance, you can use the concept of mechanical conservation of energy that confirms : U(start) + K(start) = U(final) + K(final).
So since you want to find its K(final) you can isolate it in the law and it gives you:
K(final) = U(start) + K(start) - U(final)
Consider that in halfway fall its Ug(final) value is mgh = 40[kg] · 10[m/s²] · 2.5[m] = 1000[Joule]
Now you just need to change these elements into their values(consider that K(start) is 0:
K(final) = 2000[Joule] + 0[Joule] - 1000[Joule] = 1000[J]
Hope I explained it well.