The answer should be C) Slide against each other.
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.
Answer:
Push with force of 1N
Explanation:
I have explained in the paper.
Goodluck
Answer:
31.1 N
Explanation:
m = mass attached to string = 0.50 kg
r = radius of the vertical circle = 2.0 m
v = speed of the mass at the highest point = 12 m/s
T = force of the string on the mass attached.
At the highest point, force equation is given as

Inserting the values

T = 31.1 N
Answer:
1 / f = 1 / i + 1 / o thin lens equation
1 / i = 1 / f - 1 / o = (o - f) / (o * f)
i = o * f / (o - f)
i = 54.2 * 12.7 / (54.2 - 12.7) = 16.6 cm image distance
Image is real and inverted and 16.6 / 54.2 * 6 = 1.94 cm tall