Answer:
they both weight the same
Explanation:
they both weigh one kilo so they are the same
Answer:

Explanation:
The center of mass of the system (two girls) is constant, as the velocity of the center of mass of the system is also constant.

<u>The initial velocity of the system is zero, since both girls are at rest.</u> So the velocity of the total system at any point should be zero as well.

This is true, because there is no friction between the girls and the ground. Otherwise, the velocity of the center of mass wouldn't be constant.
Answer:
The value is 
Explanation:
From the question we are told that
The diameter of the nucleus is 
The charge of the proton that makes up the nucleus is 
The energy to be impacted is 
Generally the radius of the nucleus is mathematically represented as

=> 
=> 
Generally from the law energy conservation we have that

i.e

Here

Here
is the initial kinetic energy which is mathematically represented as
Here
is the initial potential energy of the proton and the value is 0 J given that the proton is moving
Also
is mathematically represented as

Here
is the final potential energy which is mathematically represented as

Here
is the charge on the proton with a value of 
So

=> 
So

=> 
Here m is the mass of the moving proton with value 
So

=> 
=> 
Answer:
the fraction of the total energy (Etot) of the cart-spring system is elastic potential energy (Us) is 0.25
the fraction is kinetic energy (K) when the cart is at position x=A/2 is 0.75
Explanation:
the solution is in the attached Word file
I would go with c due the fact that water has tendencies to flow, meaning it will runoff and majority of the water will run off, it couldn’t be a because the fact that the grass and plant will absorb what they need. D clearly is too vague for such a question. B would be the only contesting answer but I feel c is the stronger choice because evaporations is a longer process and because of that only little amounts of water will evaporate while majority of it will become runoff due to hills, mountains, storm drains, slopes, etc.