Final answer:
When the speed of a moving object is halved, its kinetic energy is reduced to one-fourth of its original value, while its momentum is halved.
Step-by-step explanation:
When the speed of a moving object is halved, its kinetic energy is affected, not just cut in half. Kinetic energy (KE) is given by the formula ½mv2, where m is the mass of the object and v is its velocity. If the velocity is halved, the kinetic energy becomes ½m(½v)2 = ½mv2/4 = KE/4. So, when the velocity is halved, the kinetic energy is reduced to one-fourth of its original value, not halved.
Momentum (p), on the other hand, is given by the formula p = mv. If the velocity is halved, the momentum becomes mv/2, which is indeed halved. Therefore, the correct answer is that when the speed of a moving object is halved, its momentum is halved, not its kinetic energy.