A common practice drill that helps roller derby skaters gain strength and endurance -[Free] B48
A common practice drill that helps roller derby skaters gain strength and endurance is called the pushcart drill. In this drill, several skaters get in a single file line on the track and grab ahold of the waist or shoulders of the skater in front of them. The skater at the back then pushes the entire group around the track. The skaters being pushed do not help by skating themselves; they just allow themselves to roll and hang onto each other. After doing a lap or two, the front skater will fall to the back and become the next person to push the group. Tenacious D.
,
also known as Dawn, is a skater with Madison,
Physics of Roller Derby Training – Pushcart Drill
Question:
A common practice drill that helps roller derby skaters gain strength and endurance is called the pushcart drill. In this drill, several skaters get in a single file line on the track and grab the waist or shoulders of the skater in front of them. The skater at the back pushes the entire group around the track.
On which of the following variables does the work Dawn does on the skaters depend?
- Dawn’s own kinetic energy
- The total final kinetic energy of the skaters that Dawn is pushing
- The total initial kinetic energy of the skaters that Dawn is pushing
- The time taken for the skaters to reach their final kinetic energy
Answer with Full Explanation:
Step 1: Understand What “Work” Means in Physics
In physics, work is the energy transferred to an object when a force is applied over a distance. In the context of the pushcart drill, Dawn does work on her teammates by pushing them, causing them to accelerate and increase their speed.
Step 2: How Work Relates to Kinetic Energy
According to the Work-Energy Theorem, the work done on an object is equal to the change in its kinetic energy:
Work = Final Kinetic Energy − Initial Kinetic Energy
Therefore, the work Dawn does depends directly on the difference between the final and initial kinetic energies of the skaters she pushes.
Step 3: Evaluate Each Option
- Dawn’s own kinetic energy: ❌ Not relevant to the work she performs on others.
- Total final kinetic energy of skaters: ✅ Relevant. This is the energy they have after acceleration.
- Total initial kinetic energy of skaters: ✅ Relevant. Needed to calculate the energy difference.
- Time to reach final kinetic energy: ❌ Irrelevant for work (but important for power).
Final Answer:
The work Dawn does on the skaters depends on:
- The total final kinetic energy of the skaters
- The total initial kinetic energy of the skaters
These two quantities determine the net work done by Dawn. Her own kinetic energy and the time it takes are not directly involved in calculating the work done.