I attached the missing picture.
The force of seat acting on the child is a reaction the force of child pressing down on the seat. This is the third Newton's law. The force of a child pressing down the seat and the force of the seat pushing up on the child are the same.
There two forces acting on the child. The first one is the gravitational force and the second one is centrifugal force. In this example, the force of gravity is always pulling down, but centrifugal force always acts away from the center of circular motion.
Part AFor point A we have:

In this case, the forces are aligned, centrifugal is pointing up and gravitational is pulling down.
Part BAt the point, B situation is a bit more complicated. In this case force of gravity and centrifugal force are not aligned. We have to look at y components of this forces, y-axis, in this case, is just pointing upward.
Part CThe child will stay in place at point A when centrifugal force and force of gravity are in balance:
Fish swimming forward in the water, the water gets pushed backward because the fish moving forward is forcing the water to move backward, the motion forward and backward are the same, they are opposite and equal.
Answer:
umm section 2 and 4
Explanation:
because at section 2 it starts and at section 4 it moves again and stops at 3.
Answer:

Explanation:
We are asked to find the final velocity of the boat.
We are given the initial velocity, acceleration, and time. Therefore, we will use the following kinematic equation.

The initial velocity is 2.7 meters per second. The acceleration is 0.15 meters per second squared. The time is 12 seconds.
= 2.7 m/s - a= 0.15 m/s²
- t= 12 s
Substitute the values into the formula.

Multiply the numbers in parentheses.




Add.

The final velocity of the boat is <u>4.5 meters per second in the positive direction.</u>