Aperson weighing 785 newtons on the surface
of earth would weigh 298 newtons on the
surface of mars. what is the magnitude of the
gravitational field strength on the surface of
mars?
(1) 2.63 n/kg (3) 6.09 n/kg
(2) 3.72 n/kg (4) 9.81 n/kg

                      Weight anywhere = (mass) x (gravity there)

The acceleration of gravity on Earth is 9.8 m/s² .
So on Earth . . .

                       785 N = (the person's mass) x (9.8 m/s²)

Divide each side by (9.8 m/s²):

                       The person's mass = (785N) / (9.8 m/s²)


On Mars, 
                 (his weight) = (his mass) x (acceleration of gravity on Mars)

              298 newtons  =  (785/9.8  kg) x (acceleration of G on Mars)

Divide each side by  (785/9.8 kg):

           Acceleration of gravity on Mars =

                      (298 newton) / (785/9.8 kg) =  3.72 N / kg .
  

Answer

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

explanation

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

  concave means having an outline or surface that curves inward like the interior of a circle or sphere. so the mirror curves inward.