How far apart (in mm) must two point charges of 70.0 nc (typical of static electricity) be to have a force of 1.30 n between them?

r=5.824 mm

Explanation:

Given

Charge

Force between them

Electrostatic Force is given by

where and are the charge on the Particles

r=distance between them

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.