Answer:
1.99 parsecs.
Explanation:
We have been given that the most recently discovered system close to Earth is a pair of brown dwarfs known as Luhman 16. It has a distance of 6.5 light-years.
We know that one light year equals to 0.306601 parsecs. To convert 6.5 light-years to parsecs, we will multiply 0.306601 by 6.5.



Therefore, Luhman 16 is approximately 1.99 parsecs away from the Earth.
If the kinetic energy of each ball is equal to that of the other,
then
(1/2) (mass of ppb) (speed of ppb)² = (1/2) (mass of gb) (speed of gb)²
Multiply each side by 2:
(mass of ppb) (speed of ppb)² = (mass of gb) (speed of gb)²
Divide each side by (mass of gb) and by (speed of ppb)² :
(mass of ppb)/(mass of gb) = (speed of gb)²/(speed of ppb)²
Take square root of each side:
√ (ratio of their masses) = ( 1 / ratio of their speeds)²
By trying to do this perfectly rigorously and elegantly, I'm also
using up a lot of space and guaranteeing that nobody will be
able to follow what I have written. Let's just come in from the
cold, and say it the clear, easy way:
If their kinetic energies are equal, then the product of each
mass and its speed² must be the same number.
If one ball has less mass than the other one, then the speed²
of the lighter one must be greater than the speed² of the heavier
one, in order to keep the products equal.
The pingpong ball is moving faster than the golf ball.
The directions of their motions are irrelevant.
Answer:
The speed of q₂ is 
Explanation:
Given that,
Distance = 0.4 m apart
Suppose, A small metal sphere, carrying a net charge q₁ = −2μC, is held in a stationary position by insulating supports. A second small metal sphere, with a net charge of q₂ = −8μC and mass 1.50g, is projected toward q₁. When the two spheres are 0.800m apart, q₂ is moving toward q₁ with speed 20m/s.
We need to calculate the speed of q₂
Using conservation of energy



Put the value into the formula






Hence, The speed of q₂ is 