A charge Q is transfered from an initially uncharged plastic ball to an identical ball 12 cm away. The force of attraction is then 17 mN. How many electrons were transfered from one ball to the other

Explanation:

The ball from which electrons are transferred will acquire Q charge and the ball receiving electrons will acquire - Q charge . force of attraction between them

= k Q² / d²

9 x 10⁹ x Q² / .12² = 17 X 10⁻³

Q² = .0272 X 10⁻¹²

Q = .1650 X 10⁻⁶ C

No of electrons = .1650 x 10⁻⁶ / 1.6 x 10⁻¹⁹

= .103125 x 10¹³

1.03125 x 10¹²

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.

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