4. Describe why friction is the best friend and the worst enemy in NASCAR.

Friction is both the best friend and worst enemy in NASCAR because there is ways it can help with your ride or it can mess it up. It is the best friend when it comes to safety. Friction rub against the ground and keep your vehicle from sliding around. It can also slow you down if there's too much of it. This is why it is the greatest enemy. Hope this helps <3

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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