A child received a toy train set that moves on a flat track. The child pushed and released the train to move down the tracks, and the train eventually slowed. What is the force responsible for the train slowing to a stop?

A child received a toy train set that moves on a flat track. The child pushed and released the train to move down the tracks, and the train eventually slowed.  The force responsible for the train slowing to a stop was :

Friction

Explanation:

Friction is the resistance of motion when one object rubs against another. Anytime two objects rub against each other, they cause friction. Friction works against the motion and acts in the opposite direction. When one object is sliding on another it starts to slow down due to friction.Friction is the force that opposes the relative motion between the two surfaces of objects in contact. The force of friction always acts in the direction opposite to that of the applied force. Since friction is a type of force, it is measured in Newton (N).Friction is responsible for many types of motion. It helps us walk on the ground. Brakes in a car make use of friction to stop the car. Asteroids are burnt in the atmosphere before reaching Earth due to friction. It helps in the generation of heat when we rub our hands.Friction is used in car brakes, when we walk or climb a hill, making a fire, skiing down a hill, and more. Different types of surfaces create different amounts of friction.

Acetic acid  /əˈsiːtɪk/, systematically named  ethanoic acid  /ˌɛθəˈnoʊɪk/, is a colourless liquid  organic compound  with the  chemical formula  ch3cooh (also written as ch3co2h or c2h4o2). when undiluted, it is sometimes called  glacial acetic acid.  vinegar  is no less than 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water. acetic acid has a distinctive sour taste and pungent smell. in addition to household vinegar, it is mainly produced as a precursor to  polyvinyl acetate  and  cellulose acetate. it is classified as a  weak acid  since it only partially  dissociates  in solution, but concentrated acetic acid is corrosive and can attack the skin.acetic acidnamespreferred iupac nameacetic acidsystematic iupac nameethanoic acidother namesvinegar (when dilute); hydrogen acetate; methanecarboxylic acid[1][2]identifierscas number64-19-7  3d model (jsmol)interactive image3dmetb00009 reference506007chebichebi: 15366  chemblchembl539  chemspider171  drugbankdb03166  echa infocard100.000.528ec number200-580-7e numbere260  (preservatives)gmelin reference1380iuphar/bps1058keggd00010  meshacetic+acidpubchem  cid176rtecs numberaf1225000uniiq40q9n063p  un number2789inchiinchi=1s/c2h4o2/c1-2(3)4/h1h3,(h,3,4)  key:   qtbsbxvteameqo-uhfffaoysa-n  smilescc(o)=o