Answer:
The magnitude of the gravitational force acting on the lander on the surface of Mars is 512.46 N.
Explanation:
The Universal law of gravity is define as:
(1)
Where F is the gravitational force, G is gravitational constant, M is the mass of Mars, m is the mass of the lander and R is the radius of Mars.
Before replacing the values in equation 1 it is necessary to express the radius of mars in terms of meters:
R =
⇒ R = 
Finally, equation 1 can be used:

Hence, the magnitude of the gravitational force acting on the lander on the surface of Mars is 512.46 N.