Question

Shawn and his bike have a total mass of 47.7 kg. Shawn rides his bike 1.3 km in 17.5 min at a constant velocity. The acceleration of gravity is 9.8 m/s² . What is Shawn’s kinetic energy?

Answer in units of___ J.

Answer 1

Shawn's kinetic energy is calculated using the formula KE = 0.5 × mass × velocity^2. After converting time and distance to the correct units, velocity is found to be 1.238 m/s, and his kinetic energy is approximately 36.62 J.

Step-by-step explanation:

Kinetic Energy Calculation

To calculate Shawn's kinetic energy (KE), we need to use the formula for kinetic energy, which is KE = 0.5 × mass × velocity2. Since Shawn and his bike are moving at a constant velocity, we first need to convert his traveling time from minutes to seconds and his distance from kilometers to meters to find his velocity in m/s. Then, we can plug in the values into the kinetic energy formula to find the answer in joules (J), the SI unit of energy.

Step-by-Step Calculation:

1. Convert 17.5 minutes to seconds: 17.5 min × 60 sec/min = 1050 sec.
2. Convert 1.3 kilometers to meters: 1.3 km × 1000 m/km = 1300 m.
3. Calculate the velocity (v): Velocity = Distance / Time = 1300 m / 1050 sec = 1.238 m/s (approx).
4. Compute Shawn's kinetic energy: KE = 0.5 × 47.7 kg × (1.238 m/s)2 = 36.62 J (rounded to two decimal places).

Therefore, Shawn's kinetic energy while riding the bike is approximately 36.62 J.