Urgent: using hooke's law, find the force needed to stretch a spring 2 cm if it has an elastic constant of 3 n/cm

a 6 n
b 3 n
c 2/3 n
d 3/2 n

Answer :  A (6 N)

we know that

from Hook's law , F = k.x

                             where, F = force applied on spring 9N)

                                         k = spring constant  (N/cm)

                                         x = distance of spring stretched (cm)

                           Therefore,

                                        F = 2 × 3

                                        F  = 6 N

energy stored in the capacitor= 9.72 x 10⁻⁴ j

explanation:

the energy stored in the capacitor is given by

e= 1/2 c v²

e= energy stored

c= capacitance= 1.5 µc= 1.5 x 10⁻⁶f

v= potential difference=36 v

so energy stored= e= 1/2 (1.5 x 10⁻⁶) (36)²

energy stored= 9.72 x 10⁻⁴j