Hi. Can you clarify for me the equation for g-force below: F= ma + mg I got this equation from my lecturer. He asked the class to determine how was the formula above formulated. But this is not a homework. Is the equation above true for g-force? If it's true, how does the formula come about? I thought g-force is given by (as stated by Newton's law of universal gravitation): F = G m1m2/r^2 I really can't see how these two equations are equal. Could you help me out? Thanks!