Which of the following factors determines the strength of the frictional force between two surfaces? the amount of heat generated by the frictional the types of surfaces involved the objects' sizes how hard the surfaces push together

Which type of reaction is shown in this energy diagram? energy products activation energy reactants time o a. endothermic, because energy is released to the surroundings o b. exothermic, because energy is absorbed from the surroundings o c. exothermic, because energy is released to the surroundings o d. endothermic, because energy is absorbed from the surroundings