They have a north and South Pole .The opposite poles attract to each other ,the same poles repel from each other.
The angular momentum is defined as,

Acording to this text we know for conservation of angular momentum that

Where
is initial momentum
is the final momentum
How there is a difference between the stick mass and the bug mass, we define that
Mass of the bug= m
Mass of the stick=10m
At the point 0 we have that,

Where l is the lenght of the stick which is also the perpendicular distance of the bug's velocity
vector from the point of reference (O), and ve is the velocity
At the end with the collition we have

Substituting




Applying conservative energy equation we have


Replacing the values and solving

Substituting
l=\frac{13}{0.54(9.8)}

Answer:
-450 m/s
Explanation:
Momentum is conserved.
p₀ = p
0 = (1.5 kg) (1.5 m/s) + (0.005 kg) v
v = -450 m/s
It is D, you can not replace minerals. This makes them valuable.
Answer:
The energy in its ground state is 10 meV.
Explanation:
It is given that,
The energy of the electron in its first excited state is 40 meV.
Energy of the electron in any state is given by :

For ground state, n = 1
.............(1)
For first excited state, n = 2
.............(2)
Dividing equation (1) and (2), we get :


So, the energy in its ground state is 10 meV. Hence, this is the required solution.