So Hooke's law says that that law is proportional to how much I stretch the spring. Alright. So f=kx<span>. x is the length of the spring now minus its length when it's relaxed and nobody's pulling on it. k is a constant called the spring constant.</span>
        
                    
             
        
        
        
Answer:
151.9 N
Explanation:
Force = mass x acceleration
Acceleration due to gravity is 9.8 m/s^2 (you should memorize this number).
F = ma
F = (15.5)(9.8)
F = 151.9
 
        
             
        
        
        
Answer:
Where the electric potential is constant, the strength of the electric field is zero.
Explanation:
As a test charge moves in a given direction, the rate of change of the electric potential of the charge gives the potential gradient whose negative value is the same as the value of the electric field. In other words, the negative of the slope or gradient of electric potential (V) in a direction, say x, gives the electric field (Eₓ) in that direction. i.e
Eₓ = - dV / dx        ----------(i)
From equation (i) above, if electric potential (V) is constant, then the differential (which is the electric field) gives zero. 
<em>Therefore, a constant electric potential means that electric field is zero.</em>
 
        
             
        
        
        
The Newton’s law Nikolas would use to come up with this idea is the <span>Third law that states:
</span><span>When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.
</span>
So, in this case, let's name the first Body 
A which is the skateboard and the second body 
B which is <span>the compressed carbon dioxide in a fire extinguisher. Then, as shown in the figure below, according to the Third law:
</span>

<span>
</span>
 
        
        
        
Answer:
Explanation:
Newton’s Second Law of Motion says that acceleration (gaining speed) happens when a force acts on a mass (object). Riding your bicycle is a good example of this law of motion at work. Your bicycle is the mass.