Question

If Sara drives 60 miles per hour, it takes her 2 hours to reach her parents' house. Write an equation describing the relationship between Sara's speed and the time it takes her to get to her parents' house. (Note that speed and time are inversely proportional).

Answer 1

Given that

Speed = 60 miles per hour.

Time = 2 hours.

Consider the speed formula.

$\text{speed=}\frac{\text{distance}}{\text{time}}\text{ }$

Substitute speed=60 and time =2, we get

$\text{60=}\frac{\text{distance}}{\text{2}}\text{ }$

$\text{60}\times2\text{=distance }$

$\text{120=distance }$

Substitute speed=s, time=t, and distance =120 in the speed formula, we get

$s=\frac{120}{t}$

Hence the relationship between speed and time is

$s=\frac{120}{t}$