Answer:
Id say C
Explanation:
The hypotenuse for c is up and to the right so the unit vectors show that
(a) The free body of all the forces include, frictional force, weight of the box acting perpendicular and another acting parallel to the plane.
(b) When the box is sliding down, the frictional force acts towards the right.
(c) When the box slides up, the direction of the frictional force changes, it acts towards the left.
<h3>
Free body diagram</h3>
The free body diagram of all the forces on the box is obtained by noting the upward force and downward forces on the box as shown below;
/ W2
Ф → Ff
↓W1
where;
- Ff is the frictional force resisting the down motion of the box
- W1 is the perpendicular component of the box weight = Wcos(33)
- W2 is the parallel component of the box weight = Wsin(33)
(b) When the box is sliding down, the frictional force acts towards the right.
(c) When the box slides up, the direction of the frictional force changes, it acts towards the left.
Learn more about free body diagram of inclined objects here: brainly.com/question/4176810
Weight of the carriage 
Normal force 
Frictional force 
Acceleration 
Explanation:
We have to look into the FBD of the carriage.
Horizontal forces and Vertical forces separately.
To calculate Weight we know that both the mass of the baby and the carriage will be added.
- So Weight(W)
To calculate normal force we have to look upon the vertical component of forces, as Normal force is acting vertically.We have weight which is a downward force along with 
, force of 
acting vertically downward.Both are downward and Normal is upward so Normal force 
- Normal force (N)
- Frictional force (f)
To calculate acceleration we will use Newtons second law.
That is Force is product of mass and acceleration.
We can see in the diagram that 
and 
component of forces.
So Fnet = Fy(Horizontal) - f(friction) 
- Acceleration (a) =
So we have the weight of the carriage, normal force,frictional force and acceleration.
I believe the best example of Newton's First Law of motion would be the example or illustration with the basketball player. An object will move in a straight line or a given direction at a constant speed unless or until another force acts upon the object, causing a change in speed and or direction.
