IB MYP Integrated Sciences e-Assessment : Energy transfer and transformation Exam Style Practice Questions - New Syllabus
Question (3 marks)
An activity tracker, also known as a fitness tracker, is a device for monitoring and tracking fitness-related variables which can include distance walked or run, heart rate and oxygen concentration in the blood. Activity trackers are used in smart watches that are usually linked to smartphone apps.
The screen above shows that the student walked a total of $3927$ steps. State the energy transformation during the student’s walk.
▶️Answer/Explanation
Ans:
The primary energy transformation that occurs is
$
\text{Chemical Energy} \rightarrow \text{Kinetic Energy} + \text{Thermal Energy}
$
Chemical Energy: The body transfers food’s chemical energy (from glucose) to usable energy in the process of cellular respiration.
Kinetic Energy: Since the student is in motion, muscle activity generates kinetic energy.
Thermal Energy: Some energy loss occurs as heat due to muscle and metabolic activity and results in body heat and sweating.