Question

If 1.00 kilograms of coal is burned, approximately 3.00 x 107 joules (J) of energy is released. How many tons of coal, when burned, would produce approximately 9.00 x 1016 J?

Answer 1

Answer:

$3.00\times10^{6}\,tons$

Explanation:

We can resolve this problem using a proportion because the ratio tons burned and energy produced is constant, using x for tons burned of coal to produce $9.00\times10^{16}J$:

$\frac{x}{9.00\times10^{16}J}=\frac{1.00\,kg}{3.00\times10^{7}J}$

solving the proportion:

$x*3.00\times10^{7}J=1.00\,kg*9.00\times10^{16}J$

$\frac{x*\cancel{3.00\times10^{7}J}}{\cancel{3.00\times10^{7}J}}=\frac{1.00\,kg*9.00\times10^{16}J}{3.00\times10^{7}J}$

$x=\frac{9.00\times10^{16}kg*\cancel{J}}{3.00\times10^{7}\cancel{J}}=3.00\times10^{9}\,kg$

Now we have the answer but in kilograms we should convert this knowing that 1 ton = 1000 kg:

$3.00\times10^{9}\,kg=3.00\times10^{9}\,\cancel{kg}*\frac{1\,ton}{1000\,\cancel{kg}}$

$3.00\times10^{9}\,kg=3.00\times10^{6}\,tons$

Answer 2

Answer:

3.3 x 106 tons

Explanation:

Since you know that E = mc2, and both equations possess the constant speed of light, set the two equations as equivalencies. For instance, E1/m1 = E2/m2. Solve for m2.

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