Answer:
The correct reaction force in response to Heidi's action force is:
c. The friction is equal to 660 N since the beam is not accelerating.
Explanation:
Heidi's action force does not affect the beam. Since friction resists the sliding or rolling of one solid object over another, there is no friction acting on the beam, in this respect. The reaction force is what makes the dog to move because it acts on it. According to Newton's Third Law of Motion, forces always come in action-reaction pairs. This Third Law states that for every action force, there is an equal and opposite reaction force. This means that the dog exerts some force on Heidi, as he pulls it "forward with a force of 9.55 N."
The average kinetic energy of the particles is higher in the hot tea, so it also has greater thermal energy then the cold tea.
