When you increase your velocity on a skateboard, it is harder to stop. which is this an example of?

There are four units of muscles extend from z disc to z disc. They are thick filaments,myofibrils, sarcoplasmic reticulum and sarcomeres. Cross sections of the sarcomere in areas where thick and thin filaments overlap show that thick filament is surrounded by 6 thin filaments - each thin is surrounded by 3 thin