Answer:
U = (ε0AV^2) / 2d
Explanation:
Where C= capacitance of the capacitor
ε0= permittivity of free space
A= cross sectional area of plates
d= distance between the plates
V= potential difference
First, the capacitance of a capacitor is obtained by:
C = ε0A/d.
Starting at the formula , U= (CV^2)/2. Formula for energy stored in a capacitor
Substitute in for C:
U = (ε0A/d) * V^2 / 2
Hence:
U = (ε0AV^2) / 2d
8 x 10^8 = 800,000,000
In Scientific Notation, your goal is to get your the number you're multiplying by 10 (8 in this case) to be between 0 and 10. Therefore, you would NOT have 80 x 10^7 because 80 is not between 0 and 10.
Answer:
1keff=1k1+1k2
see further explanation
Explanation:for clarification
Show that the effective force constant of a series combination is given by 1keff=1k1+1k2. (Hint: For a given force, the total distance stretched by the equivalent single spring is the sum of the distances stretched by the springs in combination. Also, each spring must exert the same force. Do you see why?
From Hooke's law , we know that the force exerted on an elastic object is directly proportional to the extension provided that the elastic limit is not exceeded.
Now the spring is in series combination
F
e
F=ke
k=f/e.........*
where k is the force constant or the constant of proportionality
k=f/e
............................1
also for effective force constant
divide all through by extension
1) Total force is
Ft=F1+F2
Ft=k1e1+k2e2
F = k(e1+e2) 2)
Since force on the 2 springs is the same, so
k1e1=k2e2
e1=F/k1 and e2=F/k2,
and e1+e2=F/keq
Substituting e1 and e2, you get
1/keq=1/k1+1/k2
Hint: For a given force, the total distance stretched by the equivalent single spring is the sum of the distances stretched by the springs in combination.
Answer: having to push a rough and heavy box across the floor to move it
Explanation:
The Friction force is any force that is in opposite direction of the motion of an object or fluid due to the contact of this object or fluid with other bodies.
In this sense, there are different types of friction force thath are useful in different situations:
-The <u>Static friction force</u> prevents surfaces from slipping across each other. For example, the friction between your feet and the floor keeping you from slipping.
-The <u>kinetic friction force</u> as the force that helps the tires in a moving vehicle to slow down and stop when necessary.
However, if you want to push a heavy box across the floor to move it, the friction force will not be useful at all.