A car requires 1x10^8J of energy to drive 30km. calculate how many kilometers you could hypothetically drive using the energy contained in the rest mass of 100mg of fuel.

Ah hah! I spy a question about E = m c².

OK, here we go. Fossen your seat belt, mon,

it's going to be eh boompy rade!

E = energy equivalent of mass

m = the mass of the mass

c = the speed of light

E = (m) (c) ²

= (100 mg) (3 x 10⁸ m/s) ²

= (1 x 10⁻⁴ kg) (9 x 10¹⁶ m²/s²)

= 9 x 10¹² (kg-m²/s²)

= 9 x 10¹² (kg-m/s²) (m)

= 9 x 10¹² (newton) (m)

= 9 x 10¹² joules.

The car can go 30 km on 10⁸ J of energy.

How far can it go on 9 x 10¹² J?

(9 x 10¹² J) x (30 km / 10⁸J)

= (9 x 10⁴) x (30 km) = 2,700,000 km

= roughly 7.3 times the distance to the moon.