# Tutor profile: Chris F.

## Questions

### Subject: Basic Math

A car is traveling at 70 mph and is tailgating another car at distance of only 20 ft. If the reaction time of the tailgater is 0.5 seconds (time between seeing the brake lights of the car ahead flash and hitting the brake), how far will his car travel during his reaction time?

We will need to convert the 70 miles per hour to feet per second. Since there are 5280 ft. in 1 mile, 70 miles would be 70 x 5280 ft. = 369,600 ft. So the car travels 369,600 ft in 1 hour. There are 60 minutes in one hour and 60 seconds in 1 minute. So 1 hour = 60 minutes, and 60 minutes = 60 x 60 seconds = 3600 seconds. So the car is traveling 369,600 ft in 3600 seconds. To find the number of ft per sec, we can divide 369,600 ft by 3600 sec. 369,600 ft ÷ 3600 sec = 102.67 ft. per sec. So at 70 mph he is traveling 102 ft. per second. Therefore, with his considered reaction time (.5 sec) he will stop half the distance he will travel in one whole second. So his car will travel 51 ft within his reaction time.

### Subject: Earth Science

The soft layer of the mantle on which the tectonic plates move

The Athenosphere

### Subject: Chemistry

What is the molarity of an NaOH solution if 40.0 mL is needed to neutralize 30.0 mL of 0.144 M H2S04?

You must first write the reaction and then balance out the equation After balancing out the equation (2NaOH aq + H2SO4 aq --> Na2SO4 aq + 2H2O) Then you would need to find the Molarity of H2SO4 by using the molarity equation, .144 M = x/.030 L x= .00432 mol H2SO4 x 2 mol/ 1 mol H2SO4 = .00864 mol H+ We now know the amount of Hydrogen ions we have in the solution so we can now find the hydroxide ion ( mol H+ = mol OH ) .00864 mol OH-/ .040 L = 2.16 M NaOH We can use this method of stoichometry, because of the understanding that Hydrogen ions have an one to one ratio with Hydroxide ions.

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