Final answer:
To increase leg speed, sufficient resistance is needed during exercise to build strength and power in the muscles. In physics, more force is required as the lever arm increases in length, and resistance training can be applied through activities like weight lifting or using resistance machines.
Step-by-step explanation:
Leg speed can be increased by ensuring sufficient resistance during exercise, which in physics is often associated with the concept of force. When you exercise, resistance provides a force against which your muscles must work. Training with resistance allows you to increase strength and power, which in turn can lead to increased leg speed. In reference to the related physics concepts, it's important to note that the force is inversely proportional to the radius in circular motion, which means if you increase the length of the rope (or lever arm in exercise equipment), you have to apply more force to maintain the same speed.
Example of resistance in physical activity
Consider an exercise such as using a leg press machine; the resistance is the weight that you're pushing against. To increase leg speed, the muscle must apply a force sufficient to overcome this resistance. This builds the muscle power necessary for quick leg movements. Sufficient padding in shoes can also help in absorbing impact and reducing force transmitted to the legs when running or jogging.
Additional Example: Force in Exercise
When a person exercises with a resistance machine, such as one designed for the upper leg muscles, they must exert a force to lift the mass at a constant speed. This reflection of resistance helps strengthen the muscles over time, potentially leading to increased leg speed.