Final answer:
The kinetic energy of an 85 kg walker moving at 2.6 mph is approximately 42.7 joules. This was calculated by converting the speed to meters per second and applying the kinetic energy formula.
Step-by-step explanation:
To determine the kinetic energy of the walker, we can use the formula for kinetic energy:
KE = ½ mv²
where KE is kinetic energy, m is mass in kilograms, and v is velocity in meters per second (m/s). First, we need to convert the walker's speed from miles per hour (mph) to meters per second (m/s) using the conversion factor 1 mph = 0.44704 m/s.
So, the walker's speed in m/s is:
2.6 mph × 0.44704 m/s/mph = 1.162304 m/s
Now, we can calculate the kinetic energy:
KE = ½ × 85kg × (1.162304 m/s)²
KE = ½ × 85kg × 1.3517514 m²/s²
KE = 42.6922749 J
Therefore, the kinetic energy of the walker is approximately 42.7 joules.