Newton's first law states that an object at rest will stay at rest or an object in
motion will stay in motion and travel in a straight line, as long as no external net
force acts on it. Which of the following statements could be the best evidence of
this Law?
A. The force of the boy exerted in pulling the cart and the force of the cart
exerted on the boy.
B. You are riding in a passenger jeep that speeds up rapidly then you are
pushed backward.
C. A full shopping cart has greater mass than an empty shopping cart
D. Two groups of students playing tug-of war.