Answer:
The coefficient of static friction between the puppy and the floor is 0.7273.
Explanation:
The horizontal force applied to move the puppy from a steady state has to be greater than the force of static friction, after it is moving the force needs to be equal to be greater than the force of dynamic friction in order to maintain its movement. The force of static friction is given by:

Where
is the static friction force,
is the coefficient of static friction and
is the normal force. Since there's no angle on the flor the normal force is equal to the weight of the puppy, therefore,
, to make the puppy moving we need to use a force of 80 N, therefore,
, so we can solve for the coefficient as shown below:

The coefficient of static friction between the puppy and the floor is 0.7273.
Explanation:
Given that,
Initial speed of the electron, 
Distance, s = 5 cm = 0.05 cm
Acceleration of the electron,
(a) Let v is the electron's velocity when it emerges from this region. It can be calculated as :


v = 871779.788 m/s
or

(b) Let t is the time for which the electron take to cross the region. It can be calculated as:



Hence, this is the required solution.
I'm not quite sure what happens to Fay so I didn't finish but hope it helps