Forces on an object are combined yo determine the net force on that object.
if two forces are acting on a object in the same object the net force is the sum of both of them
if two forces are acting on an object in different directions they are subtracted
in the photo above the net force is 3
Why temperature affects heart rate in ectothermic organisms? If the temperature is within the optimal range for enzyme activity more ATP will be produced and the heart will beat faster due to increased metabolic activity and energy availability.