Answer:

The kinetic energy of an object is equal to its mass times its velocity squared, divided by two. So if the father and his daughter are both riding bikes at the same speed, their kinetic energies will be proportional to their masses. Since the father has twice the mass of his daughter, his kinetic energy will be twice as great as his daughter's.

To express this mathematically:

Father's kinetic energy = (Father's mass) * (Velocity)^2 / 2

Daughter's kinetic energy = (Daughter's mass) * (Velocity)^2 / 2

Therefore, the father's kinetic energy is twice the daughter's kinetic energy:

Father's kinetic energy = 2 * Daughter's kinetic energy