Why are the plates in a capacitor parallel to each other?
to allow each plate to become positively charged
to form a uniform electric field between the plates
to establish a potential difference between the plates
to allow each plate to hold the same amount of charge

to form a uniform electric field between the plates

Explanation:

As we know that the capacitor is a device which is used to store the electrostatic potential energy between the plates.

So here our aim is to design such a capacitor system which will store energy between two plates and that energy will be uniform if the two plates are parallel to each other

If the two plates are not parallel to each other then in that case the field between the plates becomes non uniform and that will form make the charge distribution non uniform.

So here correct answer will be

to form a uniform electric field between the plates

we need to know the time interval during which the force acts. impulse of force = momentum change

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.