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.

Beryl states that insulation with the smallest possible thermal conductivity is best to keep a house warm in winter, but worst for keeping a house cool in summer. sapphire insists the reverse is true: low thermal conductivity is good in the summer, but bad in the winter. which one, if either is correct? a. beryl, because low thermal conductivity results in low heat transfer. b. beryl, because low thermal conductivity results in high heat transfer. d. sapphire, because low thermal conductivity results in high heat transfer. e. neither, because low heat transfer is desirable both in summer and in winter.