Write an equation for this situation using F to represent the amount of fluid (saline solution) left in milliliters and t to represent the time in minutes. Hint

Question

Doctors use intravenous (IV) drips to deliver fluids and medications to patients. Suppose an IV drip starts with 1,000 ml of saline and dispenses fluid at a rate of 2.5 ml per minute.

Write an equation for this situation using F to represent the amount of fluid (saline solution) left in milliliters and t to represent the time in minutes. Hint: If you have trouble writing a model, try making a table first.

Answer 1

making a table might be helpful....at time 0, there is 1000ml. This is sometimes called the initial value. after 1 minute, you have 2.5 less, or 997.5. After 2 minutes you have 995.....so you're subtracting 2.5 ml for every minute.....so the 2.5 gets the variable.

 

t       0             1            2       3          4          5         6       7       8

ml    1000     997.5     995    992.5    990      987.5   985   982.5   980

 

So Ml = 1000-2.5t

 

Hope this helped.