How to obtain a proper following distance? when the back bumper of the vehicle ahead passes a fixed object a sign, shadow, pole or tire mark) start counting (1001 & 1002). when your front bumper reaches that spot, stop counting.

Aswimming pool whose volume is 10 comma 000 gal contains water that is 0.01% chlorine. starting at tequals0, city water containing 0.003% chlorine is pumped into the pool at a rate of 5 gal/min. the pool water flows out at the same rate. what is the percentage of chlorine in the pool after 1 hour? when will the pool water be 0.006% chlorine?