This should help
there always needs to be the two electrons first if possible the 8 electrons for each shell till the number of electron runout
C.
The train first sped up, giving it a positive acceleration in the beginning. This eliminates D since that choice states that it begins with a negative acceleration. This also eliminates B since that choice states that the train only had a negation acceleration.
Next, the train slows down, giving it a negative acceleration. We’re looking for the answer choice that starts with a positive acceleration and ends with a negative one. This makes C the correct answer. Hope this helps!
Answer:
The intensity of laser 2 is 4 times of the intensity of laser 1.
Explanation:
The intensity in terms of electric field is given by :

E is electric field
It means, 
In this problem, lasers 1 and 2 emit light of the same color, and the electric field in the beam of laser 1 is twice as strong as the e-field of laser 2.
Let E is electric field in the beam of laser 1 and E' is the electric field in the beam of laser 2. So,

We have,
E'=2E
So,

So, the intensity of laser 2 is 4 times of the intensity of laser 1.
The perfect elastic Collision ball will hit the door first because the clay is heavier and will take more time
Answer:

Explanation:
The system ball-pin is modelled by the Principle of Moment Conservation:

The velocity of the bowling ball after the collision is:
