Answer:
Explanation:
Mass of a proton, 
Mass of an electron, 
The distance between the electron and the proton is, 
We need to find the mutual attractive gravitational force between the electron and proton. The gravitational force is given by :
Where G is the universal Gravitational constant
So, the force between the electron and proton is 
.
Well, the surface of still water has surface tension. If there isn't enough mass or weight to break the surface tension, the object will float.
For this case we have that by definition, the kinetic energy is given by the following formula:
Where:
m: It is the mass
v: It is the velocity
According to the data we have to:
Substituting the values we have:
finally, the kinetic energy is 
Answer:
Option A
