Answer
Please see the work below.
Work Step by Step
(a) For moon , the kinetic energy can be determined as
$K.E=G\frac{M_m \space m}{R_M}$
We plug in the known values to obtain:
$K.E=6.67\times 10^{-11}\times \frac{7.35\times 10^{22}(39,000)}{1.74\times 10^6}$
$K.E=1.1\times 10^{11}J$
(b) For the Earth , the kinetic energy can be determined as
$K.E=G\frac{M_E \space m}{R_E}$
We plug in the known values to obtain:
$K.E=6.67\times 10^{-11}\times \frac{5.97\times 10^{24}(39,000)}{6.37\times 10^6}$
$K.E=2.4\times 10^{12}J$
