Question

a car travels from point s at (-5,7) to point t at (-5,-1). if each unit represents 20 miles, how long will it take the car to travel this distance, traveling at 40 miles per hour?

Answer 1

Answer:

The value is  $t = 4 \ hours$

Step-by-step explanation:

From the question we are told that

  The initial  position of the car is  $x_i , y_i = (-5,7)$

   The final position of the car is    $x_f , y_f = (-5,-1)$

    The speed of the car is $v = 40 \ miles / hour$

Generally the distance covered by the car along the x-axis is  

      $x = -5 - [- 5]$

=>    $x = 0$

Generally the distance covered along the y-axis is  

     $y = y_i - y_f$

=>$y = y_i - [-1]$

=>  $y = 8$

Generally the resultant distance covered is  

     $R = \sqrt{x^2 + y^2}$

=>   $R = \sqrt{0^2 + 8^2}$

=>   $R = 8$

From the question we are told that 1 unit of the distance covered is  20 miles so  

    8 units is

           $r = 8 *20$

=>        $r =160 \ miles$

Generally the time taken is mathematically represented as

       $t = \frac{r}{v}$

=>    $t = \frac{160}{ 40}$

=>    $t = 4 \ hours$