Answer:
1/2
Explanation:
We need to make a couple of considerations but basically the problem is solved through the conservation of energy.
I attached a diagram for the two surfaces and begin to make the necessary considerations.
Rough Surface,
We know that force is equal to,



Matching the two equation we have,


Applying energy conservation,





Frictionless surface




Given the description we apply energy conservation taking into account the inertia of a sphere. Then the relation between
and
is given by


Magnet moving left to right
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:

Explanation:
The momentum of the neutron before and after the decay is the same since there's no external force.

#The neutron is initially at rest, so after the decay:

#After decay, the proton has +ve direction with a velocity
while the electron moves in a negative direction with a velocity 
Therefore:

Let the energy released during the decay be Q:

Hence,Kp/Ktot is 5.444x10^(-4)