Final answer:
The kinetic energy of an 80-kg skater moving at 6.0 m/s is calculated using the formula KE = ½ m v², resulting in 1,440 joules, which is option C.
Step-by-step explanation:
The kinetic energy of a skater can be calculated using the formula:
KE = ½ m v²
where m is the mass of the skater and v is the velocity. For an 80-kg skater skating at a constant speed of 6.0 m/s:
KE = ½ × 80 kg × (6.0 m/s)²
KE = ½ × 80 kg × 36 m²/s²
KE = ½ × 80 kg × 36 J/kg·m²/s²
KE = 1440 J
Therefore, the kinetic energy of the skater is 1,440 joules, which corresponds to answer choice C.