Atrain travels from one city to another. it's initial velocity is lower than its final velocity. this is an example of

Acceleration is the variation of velocity over time .

Now, it is said that a body has a positive acceleration, when the velocity of the body increases, that is, when the final velocity is greater than the initial velocity.

It is then said that it is an accelerated movement.

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.