Final answer:
The combined kinetic energy of the 45.0-kilogram boy and the 15.0-kilogram bicycle traveling at 8.00 meters per second is 1920 joules.
Step-by-step explanation:
The combined kinetic energy (KE) of the boy and the bicycle is calculated using the formula KE = ½ mv², where m is the mass and v is the velocity. Here, you have to sum the mass of the boy and the bicycle then apply the combined mass to the formula with the given velocity.
First, combine the mass of the boy and the bicycle:
45.0 kg (boy) + 15.0 kg (bicycle) = 60.0 kg.
Now, plug the combined mass and the velocity into the kinetic energy formula:
KE = ½ × 60.0 kg × (8.00 m/s)².
KE = ½ × 60.0 kg × 64.0 m²/s²
KE = 30.0 kg × 64.0 m²/s²
KE = 1920 J.
Therefore, the combined kinetic energy of the boy and the bicycle is 1920 joules.