The surface charge density on an infinite charged plane is - 2.10 ×10−6C/m2. A proton is shot straight away from the plane at 2.40 ×106m/s. How far does the proton travel before reaching its turning point?

Explanation:

Formula to calculate electric field because of the plate is as follows.

         E =

            =

           =

Now, we will consider that equilibrium of forces are present there. So,

                   ma = qE

       a =

          =

According to the third equation of motion,

or,      d =

             =

             = 0.254 m

Thus, we can conclude that the proton will travel 0.254 m before reaching its turning point.

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.