#### Answer

(a) $KE = 1.0\times 10^{16}~J$
(b) The amount of energy delivered to the ground by the meteor was equivalent to about 2.4 megaton bombs.

#### Work Step by Step

(a) $KE = \frac{1}{2}mv^2$
$KE = \frac{1}{2}(1.4\times 10^8~kg)(1.2\times 10^4~m/s)^2$
$KE = 1.0\times 10^{16}~J$
(b) We can find the amount of energy released by a 1.0-megaton bomb.
$E = (4.184\times 10^9~J)(1.0\times 10^6)$
$E = 4.184\times 10^{15}~J$
We can consider the energy of the meteor compared to the bomb.
$\frac{1.0\times 10^{16}~J}{4.184\times 10^{15}~J} = 2.4$
The amount of energy delivered to the ground by the meteor was equivalent to about 2.4 megaton bombs.