Answer:
The change in volume is 
Solution:
As per the question:
Coefficient of linear expansion of Copper, 
Initial Temperature, T = 
= 273 K
Final Temperature, T' = 
= 273 + 100 = 373 K
Now,
Initial Volume of the block, V = 
where
V' = Final volume
Answer:
2.30 × 10⁻⁸ N if the two electrons are in a vacuum.
Explanation:
The Coulomb's Law gives the size of the electrostatic force 
between two charged objects:
,
where
is coulomb's constant. 
in vacuum.
and 
are the signed charge of the objects.
is the distance between the two objects.
For the two electrons:
.
.
.
The sign of is negative. In other words, the two electrons repel each other since the signs of their charges are the same.
I think that this is false but I am not sure
Answer:
15 N
Explanation:
According to Newton's third law of motion, to every action, there is an equal and opposite reaction. This reaction is equal in magnitude to the force acting but in an opposite direction.
Now, if the book weighs 15 N, an opposite equal force will be: N = -15 N
But the magnitude of this will be the absolute value which is 15N.
