The formula D = rt gives the distance traveled in time T at rate R. A bicyclist rides at a constant rate of 15 miles per hour. How many miles will she travel in 3.5 hours?
The answer is: [A]: 52.5 (mi.) ________________________________________ Explanation: _________________________ Use the formula: D = r*t . _________________________ {Note of interest: The formula is not unique to this specific problem; but is actually true and will appear in physics and even advanced math and calculus!). ____________________________________________ In which: D = distance traveled (which we want to solve); r = rate of travel; which we are given as: "15 mi / h" ; t = time traveled; which we are given as: "3.5 h" , ______________________________________________ We want to solve for "D". ______________________ Make sure all the units are equal (which they are!). They are all in "mi." and "hours". And the questions asks for the value in miles ___________________________________ D = r * t ; solve for "D" ; by plugging in our known values of "r" and "t": ____________________________________ → D = r * t = [tex] \frac{15 mi}{h} [/tex] * (3.5 h) ; ____________________________________ → The 2 "h's" cancel out; and we are left with: ______________________________________ → D = (15 mi.) * 3.5 = 52.5 mi. → which is answer choice: [A]. ______________________________________
