Answer
See answers.
Work Step by Step
Assume that all of the asteroid’s kinetic energy is released as destructive energy.
Find the asteroid’s mass as density multiplied by volume.
$$M=(3200kg/m^3)\frac{4 \pi}{3}(1000m)^3=1.34\times10^{13}kg$$
Now find the asteroid’s KE.
$$KE=\frac{1}{2}M(15000m/s)^2=1.5\times10^{21}J$$
How many nuclear bombs is this equivalent to?
$$ 1.5\times10^{21}J\frac{1\;bomb}{4.0\times10^{16}J}=38000\;bombs$$
