<h2>
Answer:</h2>
0.126m
<h2>
Explanation:</h2>
According to Hooke's law, the force (F) acting on a spring to cause an extension or compression (e) is given by;
F = k x e -------------------(i)
Where;
k = the spring's constant.
From the question, the force acting on the spring is the weight(W) of the mass. i.e
F = W -----------------------(ii)
<em>But;</em>
W = m x g;
where;
m = mass of the object
g = acceleration due to gravity [usually taken as 10m/s²]
<em>From equation (ii), it implies that;</em>
F = W = m x g
<em>Now substitute F = m x g into equation(i) as follows;</em>
F = k x e
m x g = k x e ------------------(iii)
<em>From the question;</em>
m = m1 = 3.5kg
k = 278N/m
<em>Substitute these values into equation (iii) as follows;</em>
3.5 x 10 = 278 x e
35 = 278e
<em>Now solve for e;</em>
e = 35/278
e = 0.126m
Therefore, the distance the spring is stretched from its unstretched length (which is the same as the extension of the spring) is 0.126m
a) earth acts as a lange magnetic. Therefore when a magnet is hanging freely, it points towards the magnetic poles (like a compass)
b) like poles repel and unlike poles attracts. We can conclude with repulsion that poles are same
c) In our everyday experience aluminum doesn't stick to magnets. (under normal circumstances aluminum isn't visibly magnetic)
The speed of a electron that is accelerated from rest through an electric potential difference of 120 V is 
<h3>
How to calculate the speed of the electron?</h3>
We know, that the energy of the system is always conserved.
Using the Law of Conservation of energy,
U=0
Here, K is the kinetic energy and U is the potential energy.
Now, substituting the formula of U and K, we get:
=0------(1)
Here,
m is the mass of the electron
v is the speed of the electron
q is the charge on the electron
V is the potential difference
Let 
and 
represent the final and initial speed.
Here, =0
Solving for , we get:
=6.49
m/s
To learn more about the conservation of energy, refer to:
brainly.com/question/2137260
#SPJ4
Neglecting friction and air resistance, the first hill must be built 4 times higher than it is now.
Answer:
A
Explanation:
A. The molecules that make up olive oil are longer than those that
make up alcohol, so they have more resistance to sliding past one
another.
Olive oils are unsaturated fats with many carbons whereas, alcohols are typically short with very few carbons.
