16.

A balloon with a radius of 16 cm has an electric charge of 4.25 × 10–9 C.

a. Determine the electric field strength at a distance of 40.0 cm from the balloon’s centre.

E=kq/r^2 (8.99 x 10^9) (4.25 x 10^-9) / (0.40)^2

=1492.5N/C

b. A balloon with a radius of 14 cm and an electric charge of 3.75 × 10–9 C is brought within the electric field of the larger balloon so their centres are 40.0 cm apart. Determine the magnitude of the electric force exerted by this electric field on the smaller balloon.

Explanation:

Electric field due to a charge at a distance r

E = k Q / r²

here Q = 4.25 x 10⁻⁹ C , r = 40 cm = .4 m , K = 8.99 x 10⁹

E = 8.99 x 10⁹ x  4.25 x 10⁻⁹ / .4²

= 238.8 N/C

b )

small ballon's centre lies at distance of 40 cm from the centre of bigger charged balloon so ,

force on smaller charged balloon

= k q₁ q₂ / r²

k = 8.99 x 10⁹ , q₁ = 4.25 x 10⁻⁹ , q₂ = 3.75 x 10⁻⁹

r = .4 m

F = 8.99 x 10⁹ x 4.25 x 10⁻⁹ x  3.75 x 10⁻⁹  / .4²

= 895.5 x 10⁻⁹ N .

magnitude of the electric force exerted by this electric field on the smaller balloon

= 895.5 x 10⁻⁹ N .

i think the answer is a, hope this is right, that would be my best guess.

b.transmitters send radio waves, and receivers capture radio waves.