Respuesta :
Beth travelled the remaining distance with an average speed of 52 mph
Solution:
Given, Beth drives 200 miles in 4 hours.
The formula for distance speed is given as:
[tex]\text { distance }=\text { speed } \times \text { time. }[/tex] --- eqn 1
Calculating time taken for 18 miles:
She drives the first 18 miles at an average speed of 36 mph.
Here distance = 18 miles
speed = 36 mph
Plugging in values in eqn 1 we get,
[tex]\begin{array}{l}{\rightarrow 18 \text { miles }=36 \mathrm{mph} \times \text { time }} \\\\ {\rightarrow \text { time }=\frac{1}{2} \text { hour }}\end{array}[/tex]
Calculating average speed for the rest of the journey:
Now, remaining distance = 200 miles – 18 miles = 182 miles
And time used for remaining journey = total time – time taken for first 18 miles
[tex]4 \text { hours }-\frac{1}{2} \text { hours }=\frac{7}{2} \text { hours }[/tex]
Plugging in values in eqn 1, we get
[tex]\begin{array}{l}{182 \text { miles }=\text { average speed } \times \frac{7}{2} \text { hours }} \\\\ {\text { Average speed }=\frac{182}{7} \times 2=52}\end{array}[/tex]
Thus the average speed for rest of journey is 52 mph
The average speed for the rest of the journey is 52miles per hour.
Given that,
Beth drives 200miles in 4 hours ,
She drives the first 18 miles at an average speed of 36 mph.
We have to find,
Her average speed for the rest of the journey.
According to the question,
She drives the first 18 miles at an average speed of 36 mph.
Here, distance = 18 miles
Speed = 36 mph
Then, Distance = speed × time
18miles = 36mph × time
Time = [tex]\frac{18}{36}[/tex] = [tex]\frac{1}{2}[/tex]
Time is half an hour.
Now,
Remaining distance = 200 - 18 = 182miles
And time use for remaining journey = [tex]4-\frac{1}{2} = \frac{7}{2}[/tex] hours.
Putting the value in the equation
182miles = average speed × [tex]\frac{7}{2}[/tex] hours.
Average speed = [tex]\frac{(182)(2)}{7}[/tex] = 52miles per hour
Hence, The average speed for the rest of the journey is 52miles per hour.
For more information about Average speed click the link given below.
https://brainly.com/question/17661499
