Answer:
An external force is a force that acts on an object within the system from outside the system. This type of force is different than an internal force, which acts between two objects that are both within the system. The net external force combines these two definitions; it is the total combined external force
Explanation:
ig the answer is true
This answer is true the earth always stays at one speed
Answer:
B
Explanation:
Spectroscopy measures electromagnetic radiation.