Question

State whether each sentence is true or false and write a sentence or two explaining your reasoning. Responses must be in complete sentences. a. Any two objects with the same acceleration must be experiencing the same net force. b. A spring exerts a force proportional to its length. c. If you hold a pen in the palm of your hand and accelerate it upwards, you must push on the pen with a larger magnitude of force than then pen pushes on your hand. d. Internal forces do not affect the motion of a system.

Answer 1

a) false. Net force depends upon mass and net acceleration. So, if acceleration is same does not mean that force is same. It can only be true when mass is equal for both objects.

b)False. A spring exerts force which is proportional to change in the length from equilibrium position.

c) False, pen will experience same force with which pen pushes your hand from newtons law.(every action has equal and opposite reaction)

d)True. Internal force dont have effect on motion of centrer of mass of the system because there is action and reaction forces inside the system acting on different partical which cancel each other on overal all.