A deep-space satellite is sent to orbit a distant planet with unknown mass. On arrival, the satellite begins its orbit and measures a gravitational pull from the
planet of 620 N. If the satellite has a mass of 450 kg and orbits the planet at a
radius of 4.0 x 106 m, what is the approximate mass of the planet? (Recall
that G = 6.67 x 10-11 N·m2/kg)
A. 7.8 x 10^23 kg
B. 2.9 x 10^22 kg
C. 4.5 x 10^24 kg
D. 3.3 x 10^23 kg

grav potential energy

truck y has a greater velocity than truck x.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.