Two gravitational forces act on a given object. How do you determine the total gravita-
tional force acting on the object?

Explanation:

Depends on the location of the two forces.  If they are aligned on the same side of the object, you would simply add.

X F1 F2

X is the object. F1 and F2 are both masses which create a gravitational force. They both are the form of Fx = G * m1 * m2 / r^2. The total force is F1 + F2

If they are are on either side of the object, you subtract.

F1 X F2

Fx = F1 - F2

Any other location of F1 and F2 is much more complicated by the use of trigonometry.

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.