<Dl> <Dd> κ = g − k, (\ displaystyle \ kappa = g-k,) </Dd> </Dl> <Dd> κ = g − k, (\ displaystyle \ kappa = g-k,) </Dd> <P> where g = 1 4 M (\ displaystyle g = (\ frac (1) (4M))) is the Schwarzschild surface gravity, and k: = M Ω + 2 (\ displaystyle k: = M \ Omega _ (+) ^ (2)) is the spring constant of the rotating black hole . Ω + (\ displaystyle \ Omega _ (+)) is the angular velocity at the event horizon . This expression gives a simple Hawking temperature of 2 π T = g − k (\ displaystyle 2 \ pi T = g-k). </P> <P> The surface gravity for the Kerr--Newman solution is </P>

How does the force due to gravity on mars compare to the force due to gravity on earth (site 1)