Newton's Third Law Force Pairs · PhysicsBowl 2017 #14
Physics · mechanics
Problem
A block is suspended in the air at the end of a string held by a person. The person pulls on the string uniformly accelerating the block upward for a short time. During this time, which one of the following choices correctly identifies the Newton's Third Law pair force to the force of the string on the block?
(A) the gravitational force from the Earth on the block
(B) the force from the string on the person
(C) the force from the person on the string
(D) the force from the block on the string
(E) the force from the person on the block