2^4/2^7 = 16/128 = 0.125
(1/2)^3= 0.125
1/8= 0.125
a and f are equivalent
<span>Radius, the distance from the centre = 0.390
Electric field is equal to half of the magnitude. E2 = E / 2
Given
E1 = E2
E1 = k x Q / r^2
E2 = (k x Q / r2^2) / 2
Equating the both we get 2 x r^2 = r2^2
r2 = square root of (2 x r1^2) = square root of (2) x r = 1.414 x 0.390
r2 = 1.414 x 0.390 = 0.551 m</span>
-- You've GOT the kinetic energy of the bullet.
-- That's the amount of work that has to be done to stop it.
-- work = (avg force) x (penetration) and they just gave you the average force.
-- Did you think it would be this easy ?
