<span>The
thermal energy found in a piece of coal is lesser than in the thermal energy in
a newly opened coal mine. The newly opened coal mine requires a greater thermal
energy to really open it due to its solid structure. Whereas in a piece of
coal, it only requires a lesser amount of thermal energy to extract it.</span>
Answer:
6844.5 m/s.
Explanation:
To get the speed of the satellite, the centripetal force on it must be enough to change its direction. This therefore means that the centripetal force must be equal to the gravitational force.
Formula for centripetal force is;
F_c = mv²/r
Formula for gravitational force is:
F_g = GmM/r²
Thus;
mv²/r = GmM/r²
m is the mass of the satellite and M is mass of the earth.
Making v the subject, we have;
v = √(GM/r)
We are given;
G = 6.67 × 10^(-11) m/kg²
M = 5.97 × 10^(24) kg
r = 8500 km = 8500000
Thus;
v = √((6.67 × 10^(-11) × (5.97 × 10^(24)) /8500000) = 6844.5 m/s.
