Final answer:
Doubling the mass of the bicycle while keeping the speed constant results in a doubling of the kinetic energy to 248 J.
Step-by-step explanation:
If a bicycle with a certain mass has a kinetic energy (KE) of 124 J, and we want to know the kinetic energy if the mass is doubled but the speed remains the same, we can use the kinetic energy formula KE = ½mv², where m is mass and v is velocity. Given that the kinetic energy is directly proportional to the mass, if the mass doubles, the kinetic energy will also double, assuming the velocity does not change.
Therefore, if the original kinetic energy of the bicycle is 124 J, and we double the mass while keeping the speed constant, the new kinetic energy will be 2 × 124 J = 248 J.