If the train moves sufficiently fast, is it possible, according to experimenters on the ground, for the entire train to be inside the tunnel at one instant of time?

Explanation:

One of the consecuences of Special Theory of Relativity is that when bodies move its length in the direction of the movement will decrease, and decrease will become bigger as speed goes up. At speed close to speed of light such decrease could be such as to make train become a point, of course tunnel is fixed it will not change, but close to light speed means somethyng like 300000 km/sec therefore could be just one instant of time inside tunnel no matter how long it is  

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.