11 Years
Usually sunspot and solar flare cycles vary. But the average duration occurs every 11 years, sometimes 9-14 years as well.
The electrostatic force between two charged objects is given by

where
k is the Coulomb's constant
q1 is the charge of the first object
q2 is the charge of the second object
r is the separation between the two objects
In our problem:



So if we plug these numbers into the equation, we can find the electrostatic force between the two objects:
<span> thermal energy which, by causing pressure and performing work on the pistons, is transformed into the mechanical energy that accelerates the vehicle (increasing its kinetic energy).</span>
Answer:
C
Explanation:
intensity = Power delivered by the sound (Watt)/ Surounding Area (m²)
I = P/A
A = πr²
r = is the distance between you and the cricket.
so in other form we can get
I = P/πr²
let take I(1) as first intensitilynyou heard and I(2) as the increased intensity.
I(1) / I(2) = r(2)² / r(1)²
1/4 = r(2)²/r(1)²
1/2 = r(2) / r(1)
r(2) = ½ r(1)
or r(2) is decreaases by a factor of 2.