If a satellite of mass 400 kg revolves around the earth in an orbit with speed 200 m/s then its potential energy is

Question

If a satellite of mass 400 kg revolves around the earth in an orbit with speed 200 m/s then its potential energy is (A) -1.2 MJ (B) -8.0 MJ (C) -16 MJ (D) -2.4 MJ

Tardigrade Admin · Accepted Answer

For a satellite, P.E =-(G M m/r) m = mass of satellite r = radius of orbit K.E =(1/2) m v2=(G M m/2 r)=-( text P.E /2) ⇒ P.E =-m v2 =-400 × 4 × 104 =-16 MJ

Q. If a satellite of mass $400 k g$ revolves around the earth in an orbit with speed $200 m / s$ then its potential energy is

-1.2 MJ

-8.0 MJ

-16 MJ

-2.4 MJ

For a satellite,
$P . E = - \frac{GM m}{r}$
$m =$ mass of satellite
$r =$ radius of orbit
$K . E = \frac{1}{2} m v^{2} = \frac{GM m}{2 r} = - \frac{P.E}{2}$
$\Rightarrow P . E = - m v^{2}$
$= - 400 \times 4 \times 1 0^{4}$
$= - 16 M J$

Q. If a satellite of mass 400kg revolves around the earth in an orbit with speed 200m/s then its potential energy is