Answer:
1.5x10^-4C
C=Couloumb's
Explanation:
Expression for the electric force between the two charges is given by -
F = (k*q1*q2) / r^2
Here, k = constant = 9 x 10^9 N*m^2 / C^2
F=25N
q1 = 1.9x10^-6 x 10^-6 C
q2 = ?
r = 0.32m
Substitute the given values in the above expression -
25N= 9x10^9 *1.9x10^-6 *q2 / 0.32m^2
25N= 17,100*q2 / 0.1024m
Next part is algebra multiply both sides by 0.1024 to remove denominator
2.56=17,100*q2
Divide both sides to isolate q2
q2= 1.5x10^-4C
Answer:
Let the mass of the book be "m", acceleration due to gravity be "g", velocity be "v" and height be "h".
Now if we are holding a book at a certain height (h), <em><u>the potential energy will be maximum which is equal to mass× acceleration due to gravity× height (= mgh)</u>.</em>
(Remember: kinetic energy =0)
Now we consider that the book is dropped, in this case a force will act downward towards the centre of the earth, <em><u>Force= mass× acceleration due to gravity (F=mg)</u></em>. It is equal to the weight of the book.
While the book is falling, the potential energy stored in the book converts into kinetic energy and strikes the floor with <em><u>the maximum kinetic energy= (1/2)×mass×velocity² (=1/2mv²)</u>.</em>
(Remember: kinetic energy=0)
Due to this process the whole energy is conserved.
As the potential energy decreases kinetic energy increases.
