A student pedals an exercise bicycle fixed rigidly to the floor. After 10min, the pedals have moved through a total length of 1.2km relative to the ground. What is the work done by the student on the bicycle considered as a system?
a) Positive, because the pedals moved 1.2km while the student pushed them
b) Negative, because the student’s force is opposite to the motion of the pedals
c) Zero, because the displacement of the bicycle as a whole is zero
d) Cannot be determined without knowing the magnitude of the force applied