Question

A quantity of energy equal to 8.90 × 1012 joules was emitted from a nuclear reaction. What amount of mass was required to be converted to yield this amount of energy?
9.90 × 10-5 kg

2.96 × 10-4 kg

2.67 × 104 kg

8.01 × 105 kg

Answer 1

Answer : The amount of mass required will be, $9.90\times 10^{-5}Kg$

Explanation :

The formula used for energy is :

$E=m\times c^2$

where,

E = energy = $8.90\times 10^{12}J$

m = mass = ?

c = speed of light = $3\times 10^8m/s$

Now put all the given values in this formula, we get :

$8.90\times 10^{12}J=m\times (3\times 10^8m/s)^2$

$m=9.90\times 10^{-5}Kg$

Therefore, the amount of mass required will be, $9.90\times 10^{-5}Kg$

Answer 2

E = mc^2
E = 8.90 * 10^12 Joules
c = 3 * 10^8 m/s
m = ????

8.90 * 10^12 = m * (3 * 10^8)^2
8.90 * 10^12 = m * 9 * 10^16
9.889 * 10^-4 kg = m <<<<< answer