This question apparently wants you to get comfortable with E = m c² . But I must say, this question is a lame way to do it.
c = 3 x 10⁸ m/s E = m c²
1.03 x 10⁻¹³ joule = (m) (3 x 10⁸ m/s)²
Divide each side by (3 x 10⁸ m/s)²:
Mass = (1.03 x 10⁻¹³ joule) / (9 x 10¹⁶ m²/s²)
= (1.03 / 9) x (10⁻¹³ ⁻ ¹⁶) (kg)
= 1.144 x 10⁻³⁰ kg . (choice-1)
This is roughly the mass of (1 and 1/4) electrons, so it seems that it could never happen in nature. The question is just an exercise in arithmetic, and not a particularly interesting one. ______________________________________
Something like this could have been much more impressive:
The Braidwood Nuclear Power Generating Station in northeastern Ilinois USA serves Chicago and northern Illinois with electricity. <span>The station has two pressurized water reactors, which can generate a net total of 2,242 megawatts at full capacity, making it the largest nuclear plant in the state. If the Braidwood plant were able to completely convert mass to energy, how much mass would it need to convert in order to provide the total electrical energy that it generates in a year, operating at full capacity ?
Energy = (2,242 x 10⁶ joule/sec) x (86,400 sec/day) x (365 da/yr)
= (2,242 x 10⁶ x 86,400 x 365) joules
= 7.0704 x 10¹⁶ joules .
How much converted mass is that ?
E = m c²
Divide each side by c² : Mass = E / c² . c = 3 x 10⁸ m/s
Mass = (7.0704 x 10¹⁶ joules) / (9 x 10¹⁶ m²/s²)
= 0.786 kilogram ! ! !
THAT should impress us ! If I've done the arithmetic correctly, then roughly (1 pound 11.7 ounces) of mass, if completely converted to energy, would provide all the energy generated by the largest nuclear power plant in Illinois, operating at max capacity for a year !
These are known as balanced forces because they will not change the motion of the object, and it will remain at rest unless forces become unbalanced- meaning they would be unequal and not opposing.
