The forces acting on a child sitting in a seat are described by the free-body diagram shown. what is the net force acting on the child?
a. –100 n
b. 0 n
c. 100 n
d. 200 n

option B

0 N

Explanation:

Since, two forces are acting on the child sitting in a seat

Fn = 100N

Fg = -100N

Resultant force = sum of all forces

                           = 100 + (-100)

                           = 0  

The two forces have same magnitude but in opposite directions, so the net force (resultant of the two forces) is zero.

And,

secondly, the child is stationary so it obvious that resultant force acting in the object is zero.

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.