Tutor profile: Julia D.
Subject: Basic Math
What is 10% of 200?
in order to find 10% it is easiest to change it to a decimal, 0.1. 0.1 x 200 is 20 because you have to move the decimal point over one. Therefore, your answer is 20.
Please describe how a neuron fires.
Neurons are kept at -80 mV as a resting potential, meaning at rest they are already polarized to be very negatively charged. However, upon activation of sodium channels, more positive ions are flowing into the cell and then the cell is getting closer to 0 mV, meaning it is now depolarizing. This process of depolarization activates voltage-gated calcium channels at a specific voltage threshold and once this is surpassed, now calcium ions flow in. Because calcium has a 2+ charge and there is so little calcium usually in the cell, this flux of ions causes a rapid depolarization and action potential. Finally, potassium rectifying channels and chloride channels turn on and end the peak of the action potential and begin to repolarize and even hyperpolarize the cell. This hyperpolarization phase is important and provides a refractory period in order to space out the neurons firing.
A car averages 27 miles per gallon. If gas costs $4.04 per gallon, which of the following is closest to how much the gas would cost for this car to travel 2,727 typical miles?
Since you're going 2727 miles, first we have to figure out how many gallons we would utilize. 2727 miles of total distance / 27 miles / gallon = 101 gallons. Now, given that a gallon of gas costs $4.04 and we're utilizing 101 gallons, 101*4.04 = $408.04. That is your answer!
needs and Julia will reply soon.