When a person steps forward out of a small boat onto a dock, the boat recoils backward in the water. why does this occur? ?

Due to conservation of momentum

Explanation:

We know that if there is no any force acting on the system then  the total linear momentum of system will remain conserve.We know that linear momentum given as

P = m x v

When person steps forward then velocity of person changes it means that the linear momentum also changes to balance this change in linear momentum the boat will move away from the bank. Because the linear momentum should be conserve.

root word, prefixes, and suffixes

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.