My guess would be about 10 years because stars are hot balls of light that are reflections from years ago so it would most likely take awhile
Answer:


Explanation:
Here mass density of rod is varying so we have to use the concept of integration to find mass and location of center of mass.
At any distance x from point A mass density


Lets take element mass at distance x
dm =λ dx
mass moment of inertia

So total moment of inertia

By putting the values

By integrating above we can find that

Now to find location of center mass


Now by integrating the above


So mass moment of inertia
and location of center of mass 
Answer: Option (C) is the correct answer.
Explanation:
As we know that metals are able to conduct electricity so, when a negatively charges rod is kept closer to the left sphere then electrons will enter the sphere.
Since, like charges repel each other. Hence, some of the negative changes from the rod will repel the negative charges of left sphere.
As both left and right spheres are touching each other so, the electrons will move towards the right sphere. As a result, there will be too many electrons (negative charge) present on the right sphere and very less electrons present in the left sphere.
Thus, we can conclude that the statement right sphere is negatively charged, another is charged positively, is true.
Answer:
Explanation:
Given a school bus.
Let say initially the school bus is traveling with speed "v"
Let assume mass of school bus is "m"
Then, the initial kinetic energy is
K.E_initial = ½mv²
Now, if the initial velocity is tripled,
Then, the new velocity is
v_new = 3v.
Note: the mass of the school does not change it is constant
Then, new kinetic energy is
K.E_new = ½m(v_new)²
v_new = 3v
Then,
K.E_new = ½m(3v)²
K.E_new = ½m × 9v²
K.E_new = 9 × ½mv²
Since K.E = ½mv²
Then,
K.E_new = 9 × K.E
So, the new kinetic energy will be 9 times the initial kinetic energy.
So, option D is correct
D. It will be nine times greater.
Answer:

Explanation:
= Initial pressure = 
= Initial volume
= Final volume = 
Temperature is the same in the initial and final state
From the ideal gas law we have

The final pressure of the system is
.