A child’s toy is suspended from the ceiling by means of a string. The Earth pulls downward on the toy with its weight force of 8 N. If this is the “action force,” what is the “reaction force”?

A) the string pulling downward on the ceiling with an 8-N force
B) the ceiling pulling upward on the string with an 8-N force
C) the string pulling upward on the toy with an 8-N force
D) the toy pulling upward on the Earth with an 8-N force
E) the toy pushing downward on the Earth with an 8-N force

answer:

D) the toy pulling upward on the Earth with an 8-N force